src/webkit/child/webkitplatformsupport_impl.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "webkit/child/webkitplatformsupport_impl.h"
   6
   7 #include <math.h>
   8
   9 #include <vector>
  10
  11 #include "base/allocator/allocator_extension.h"
  12 #include "base/bind.h"
  13 #include "base/files/file_path.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/singleton.h"
  16 #include "base/message_loop/message_loop.h"
  17 #include "base/metrics/histogram.h"
  18 #include "base/metrics/sparse_histogram.h"
  19 #include "base/metrics/stats_counters.h"
  20 #include "base/platform_file.h"
  21 #include "base/process/process_metrics.h"
  22 #include "base/rand_util.h"
  23 #include "base/strings/string_number_conversions.h"
  24 #include "base/strings/string_util.h"
  25 #include "base/strings/utf_string_conversions.h"
  26 #include "base/synchronization/lock.h"
  27 #include "base/sys_info.h"
  28 #include "base/time/time.h"
  29 #include "grit/blink_resources.h"
  30 #include "grit/webkit_resources.h"
  31 #include "grit/webkit_strings.h"
  32 #include "net/base/data_url.h"
  33 #include "net/base/mime_util.h"
  34 #include "net/base/net_errors.h"
  35 #include "third_party/WebKit/public/platform/WebData.h"
  36 #include "third_party/WebKit/public/platform/WebString.h"
  37 #include "ui/base/layout.h"
  38 #include "webkit/child/webkit_child_helpers.h"
  39 #include "webkit/child/websocketstreamhandle_impl.h"
  40 #include "webkit/child/weburlloader_impl.h"
  41 #include "webkit/common/user_agent/user_agent.h"
  42
  43 #if defined(OS_ANDROID)
  44 #include "base/android/sys_utils.h"
  45 #endif
  46
  47 #if !defined(NO_TCMALLOC) && defined(USE_TCMALLOC) && !defined(OS_WIN)
  48 #include "third_party/tcmalloc/chromium/src/gperftools/heap-profiler.h"
  49 #endif
  50
  51 using blink::WebData;
  52 using blink::WebLocalizedString;
  53 using blink::WebString;
  54 using blink::WebSocketStreamHandle;
  55 using blink::WebURL;
  56 using blink::WebURLError;
  57 using blink::WebURLLoader;
  58
  59 namespace {
  60
  61 // A simple class to cache the memory usage for a given amount of time.
  62 class MemoryUsageCache {
  63  public:
  64   // Retrieves the Singleton.
  65   static MemoryUsageCache* GetInstance() {
  66     return Singleton<MemoryUsageCache>::get();
  67   }
  68
  69   MemoryUsageCache() : memory_value_(0) { Init(); }
  70   ~MemoryUsageCache() {}
  71
  72   void Init() {
  73     const unsigned int kCacheSeconds = 1;
  74     cache_valid_time_ = base::TimeDelta::FromSeconds(kCacheSeconds);
  75   }
  76
  77   // Returns true if the cached value is fresh.
  78   // Returns false if the cached value is stale, or if |cached_value| is NULL.
  79   bool IsCachedValueValid(size_t* cached_value) {
  80     base::AutoLock scoped_lock(lock_);
  81     if (!cached_value)
  82       return false;
  83     if (base::Time::Now() - last_updated_time_ > cache_valid_time_)
  84       return false;
  85     *cached_value = memory_value_;
  86     return true;
  87   };
  88
  89   // Setter for |memory_value_|, refreshes |last_updated_time_|.
  90   void SetMemoryValue(const size_t value) {
  91     base::AutoLock scoped_lock(lock_);
  92     memory_value_ = value;
  93     last_updated_time_ = base::Time::Now();
  94   }
  95
  96  private:
  97   // The cached memory value.
  98   size_t memory_value_;
  99
 100   // How long the cached value should remain valid.
 101   base::TimeDelta cache_valid_time_;
 102
 103   // The last time the cached value was updated.
 104   base::Time last_updated_time_;
 105
 106   base::Lock lock_;
 107 };
 108
 109 }  // anonymous namespace
 110
 111 namespace webkit_glue {
 112
 113 static int ToMessageID(WebLocalizedString::Name name) {
 114   switch (name) {
 115     case WebLocalizedString::AXAMPMFieldText:
 116       return IDS_AX_AM_PM_FIELD_TEXT;
 117     case WebLocalizedString::AXButtonActionVerb:
 118       return IDS_AX_BUTTON_ACTION_VERB;
 119     case WebLocalizedString::AXCheckedCheckBoxActionVerb:
 120       return IDS_AX_CHECKED_CHECK_BOX_ACTION_VERB;
 121     case WebLocalizedString::AXDateTimeFieldEmptyValueText:
 122       return IDS_AX_DATE_TIME_FIELD_EMPTY_VALUE_TEXT;
 123     case WebLocalizedString::AXDayOfMonthFieldText:
 124       return IDS_AX_DAY_OF_MONTH_FIELD_TEXT;
 125     case WebLocalizedString::AXHeadingText:
 126       return IDS_AX_ROLE_HEADING;
 127     case WebLocalizedString::AXHourFieldText:
 128       return IDS_AX_HOUR_FIELD_TEXT;
 129     case WebLocalizedString::AXImageMapText:
 130       return IDS_AX_ROLE_IMAGE_MAP;
 131     case WebLocalizedString::AXLinkActionVerb:
 132       return IDS_AX_LINK_ACTION_VERB;
 133     case WebLocalizedString::AXLinkText:
 134       return IDS_AX_ROLE_LINK;
 135     case WebLocalizedString::AXListMarkerText:
 136       return IDS_AX_ROLE_LIST_MARKER;
 137     case WebLocalizedString::AXMediaDefault:
 138       return IDS_AX_MEDIA_DEFAULT;
 139     case WebLocalizedString::AXMediaAudioElement:
 140       return IDS_AX_MEDIA_AUDIO_ELEMENT;
 141     case WebLocalizedString::AXMediaVideoElement:
 142       return IDS_AX_MEDIA_VIDEO_ELEMENT;
 143     case WebLocalizedString::AXMediaMuteButton:
 144       return IDS_AX_MEDIA_MUTE_BUTTON;
 145     case WebLocalizedString::AXMediaUnMuteButton:
 146       return IDS_AX_MEDIA_UNMUTE_BUTTON;
 147     case WebLocalizedString::AXMediaPlayButton:
 148       return IDS_AX_MEDIA_PLAY_BUTTON;
 149     case WebLocalizedString::AXMediaPauseButton:
 150       return IDS_AX_MEDIA_PAUSE_BUTTON;
 151     case WebLocalizedString::AXMediaSlider:
 152       return IDS_AX_MEDIA_SLIDER;
 153     case WebLocalizedString::AXMediaSliderThumb:
 154       return IDS_AX_MEDIA_SLIDER_THUMB;
 155     case WebLocalizedString::AXMediaCurrentTimeDisplay:
 156       return IDS_AX_MEDIA_CURRENT_TIME_DISPLAY;
 157     case WebLocalizedString::AXMediaTimeRemainingDisplay:
 158       return IDS_AX_MEDIA_TIME_REMAINING_DISPLAY;
 159     case WebLocalizedString::AXMediaStatusDisplay:
 160       return IDS_AX_MEDIA_STATUS_DISPLAY;
 161     case WebLocalizedString::AXMediaEnterFullscreenButton:
 162       return IDS_AX_MEDIA_ENTER_FULL_SCREEN_BUTTON;
 163     case WebLocalizedString::AXMediaExitFullscreenButton:
 164       return IDS_AX_MEDIA_EXIT_FULL_SCREEN_BUTTON;
 165     case WebLocalizedString::AXMediaShowClosedCaptionsButton:
 166       return IDS_AX_MEDIA_SHOW_CLOSED_CAPTIONS_BUTTON;
 167     case WebLocalizedString::AXMediaHideClosedCaptionsButton:
 168       return IDS_AX_MEDIA_HIDE_CLOSED_CAPTIONS_BUTTON;
 169     case WebLocalizedString::AXMediaAudioElementHelp:
 170       return IDS_AX_MEDIA_AUDIO_ELEMENT_HELP;
 171     case WebLocalizedString::AXMediaVideoElementHelp:
 172       return IDS_AX_MEDIA_VIDEO_ELEMENT_HELP;
 173     case WebLocalizedString::AXMediaMuteButtonHelp:
 174       return IDS_AX_MEDIA_MUTE_BUTTON_HELP;
 175     case WebLocalizedString::AXMediaUnMuteButtonHelp:
 176       return IDS_AX_MEDIA_UNMUTE_BUTTON_HELP;
 177     case WebLocalizedString::AXMediaPlayButtonHelp:
 178       return IDS_AX_MEDIA_PLAY_BUTTON_HELP;
 179     case WebLocalizedString::AXMediaPauseButtonHelp:
 180       return IDS_AX_MEDIA_PAUSE_BUTTON_HELP;
 181     case WebLocalizedString::AXMediaSliderHelp:
 182       return IDS_AX_MEDIA_SLIDER_HELP;
 183     case WebLocalizedString::AXMediaSliderThumbHelp:
 184       return IDS_AX_MEDIA_SLIDER_THUMB_HELP;
 185     case WebLocalizedString::AXMediaCurrentTimeDisplayHelp:
 186       return IDS_AX_MEDIA_CURRENT_TIME_DISPLAY_HELP;
 187     case WebLocalizedString::AXMediaTimeRemainingDisplayHelp:
 188       return IDS_AX_MEDIA_TIME_REMAINING_DISPLAY_HELP;
 189     case WebLocalizedString::AXMediaStatusDisplayHelp:
 190       return IDS_AX_MEDIA_STATUS_DISPLAY_HELP;
 191     case WebLocalizedString::AXMediaEnterFullscreenButtonHelp:
 192       return IDS_AX_MEDIA_ENTER_FULL_SCREEN_BUTTON_HELP;
 193     case WebLocalizedString::AXMediaExitFullscreenButtonHelp:
 194       return IDS_AX_MEDIA_EXIT_FULL_SCREEN_BUTTON_HELP;
 195     case WebLocalizedString::AXMediaShowClosedCaptionsButtonHelp:
 196       return IDS_AX_MEDIA_SHOW_CLOSED_CAPTIONS_BUTTON_HELP;
 197     case WebLocalizedString::AXMediaHideClosedCaptionsButtonHelp:
 198       return IDS_AX_MEDIA_HIDE_CLOSED_CAPTIONS_BUTTON_HELP;
 199     case WebLocalizedString::AXMillisecondFieldText:
 200       return IDS_AX_MILLISECOND_FIELD_TEXT;
 201     case WebLocalizedString::AXMinuteFieldText:
 202       return IDS_AX_MINUTE_FIELD_TEXT;
 203     case WebLocalizedString::AXMonthFieldText:
 204       return IDS_AX_MONTH_FIELD_TEXT;
 205     case WebLocalizedString::AXRadioButtonActionVerb:
 206       return IDS_AX_RADIO_BUTTON_ACTION_VERB;
 207     case WebLocalizedString::AXSecondFieldText:
 208       return IDS_AX_SECOND_FIELD_TEXT;
 209     case WebLocalizedString::AXTextFieldActionVerb:
 210       return IDS_AX_TEXT_FIELD_ACTION_VERB;
 211     case WebLocalizedString::AXUncheckedCheckBoxActionVerb:
 212       return IDS_AX_UNCHECKED_CHECK_BOX_ACTION_VERB;
 213     case WebLocalizedString::AXWebAreaText:
 214       return IDS_AX_ROLE_WEB_AREA;
 215     case WebLocalizedString::AXWeekOfYearFieldText:
 216       return IDS_AX_WEEK_OF_YEAR_FIELD_TEXT;
 217     case WebLocalizedString::AXYearFieldText:
 218       return IDS_AX_YEAR_FIELD_TEXT;
 219     case WebLocalizedString::CalendarClear:
 220       return IDS_FORM_CALENDAR_CLEAR;
 221     case WebLocalizedString::CalendarToday:
 222       return IDS_FORM_CALENDAR_TODAY;
 223     case WebLocalizedString::DateFormatDayInMonthLabel:
 224       return IDS_FORM_DATE_FORMAT_DAY_IN_MONTH;
 225     case WebLocalizedString::DateFormatMonthLabel:
 226       return IDS_FORM_DATE_FORMAT_MONTH;
 227     case WebLocalizedString::DateFormatYearLabel:
 228       return IDS_FORM_DATE_FORMAT_YEAR;
 229     case WebLocalizedString::DetailsLabel:
 230       return IDS_DETAILS_WITHOUT_SUMMARY_LABEL;
 231     case WebLocalizedString::FileButtonChooseFileLabel:
 232       return IDS_FORM_FILE_BUTTON_LABEL;
 233     case WebLocalizedString::FileButtonChooseMultipleFilesLabel:
 234       return IDS_FORM_MULTIPLE_FILES_BUTTON_LABEL;
 235     case WebLocalizedString::FileButtonNoFileSelectedLabel:
 236       return IDS_FORM_FILE_NO_FILE_LABEL;
 237     case WebLocalizedString::InputElementAltText:
 238       return IDS_FORM_INPUT_ALT;
 239     case WebLocalizedString::KeygenMenuHighGradeKeySize:
 240       return IDS_KEYGEN_HIGH_GRADE_KEY;
 241     case WebLocalizedString::KeygenMenuMediumGradeKeySize:
 242       return IDS_KEYGEN_MED_GRADE_KEY;
 243     case WebLocalizedString::MissingPluginText:
 244       return IDS_PLUGIN_INITIALIZATION_ERROR;
 245     case WebLocalizedString::MultipleFileUploadText:
 246       return IDS_FORM_FILE_MULTIPLE_UPLOAD;
 247     case WebLocalizedString::OtherColorLabel:
 248       return IDS_FORM_OTHER_COLOR_LABEL;
 249     case WebLocalizedString::OtherDateLabel:
 250         return IDS_FORM_OTHER_DATE_LABEL;
 251     case WebLocalizedString::OtherMonthLabel:
 252       return IDS_FORM_OTHER_MONTH_LABEL;
 253     case WebLocalizedString::OtherTimeLabel:
 254       return IDS_FORM_OTHER_TIME_LABEL;
 255     case WebLocalizedString::OtherWeekLabel:
 256       return IDS_FORM_OTHER_WEEK_LABEL;
 257     case WebLocalizedString::PlaceholderForDayOfMonthField:
 258       return IDS_FORM_PLACEHOLDER_FOR_DAY_OF_MONTH_FIELD;
 259     case WebLocalizedString::PlaceholderForMonthField:
 260       return IDS_FORM_PLACEHOLDER_FOR_MONTH_FIELD;
 261     case WebLocalizedString::PlaceholderForYearField:
 262       return IDS_FORM_PLACEHOLDER_FOR_YEAR_FIELD;
 263     case WebLocalizedString::ResetButtonDefaultLabel:
 264       return IDS_FORM_RESET_LABEL;
 265     case WebLocalizedString::SearchableIndexIntroduction:
 266       return IDS_SEARCHABLE_INDEX_INTRO;
 267     case WebLocalizedString::SearchMenuClearRecentSearchesText:
 268       return IDS_RECENT_SEARCHES_CLEAR;
 269     case WebLocalizedString::SearchMenuNoRecentSearchesText:
 270       return IDS_RECENT_SEARCHES_NONE;
 271     case WebLocalizedString::SearchMenuRecentSearchesText:
 272       return IDS_RECENT_SEARCHES;
 273     case WebLocalizedString::SubmitButtonDefaultLabel:
 274       return IDS_FORM_SUBMIT_LABEL;
 275     case WebLocalizedString::ThisMonthButtonLabel:
 276       return IDS_FORM_THIS_MONTH_LABEL;
 277     case WebLocalizedString::ThisWeekButtonLabel:
 278       return IDS_FORM_THIS_WEEK_LABEL;
 279     case WebLocalizedString::ValidationBadInputForDateTime:
 280       return IDS_FORM_VALIDATION_BAD_INPUT_DATETIME;
 281     case WebLocalizedString::ValidationBadInputForNumber:
 282       return IDS_FORM_VALIDATION_BAD_INPUT_NUMBER;
 283     case WebLocalizedString::ValidationPatternMismatch:
 284       return IDS_FORM_VALIDATION_PATTERN_MISMATCH;
 285     case WebLocalizedString::ValidationRangeOverflow:
 286       return IDS_FORM_VALIDATION_RANGE_OVERFLOW;
 287     case WebLocalizedString::ValidationRangeOverflowDateTime:
 288       return IDS_FORM_VALIDATION_RANGE_OVERFLOW_DATETIME;
 289     case WebLocalizedString::ValidationRangeUnderflow:
 290       return IDS_FORM_VALIDATION_RANGE_UNDERFLOW;
 291     case WebLocalizedString::ValidationRangeUnderflowDateTime:
 292       return IDS_FORM_VALIDATION_RANGE_UNDERFLOW_DATETIME;
 293     case WebLocalizedString::ValidationStepMismatch:
 294       return IDS_FORM_VALIDATION_STEP_MISMATCH;
 295     case WebLocalizedString::ValidationStepMismatchCloseToLimit:
 296       return IDS_FORM_VALIDATION_STEP_MISMATCH_CLOSE_TO_LIMIT;
 297     case WebLocalizedString::ValidationTooLong:
 298       return IDS_FORM_VALIDATION_TOO_LONG;
 299     case WebLocalizedString::ValidationTypeMismatch:
 300       return IDS_FORM_VALIDATION_TYPE_MISMATCH;
 301     case WebLocalizedString::ValidationTypeMismatchForEmail:
 302       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL;
 303     case WebLocalizedString::ValidationTypeMismatchForEmailEmpty:
 304       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_EMPTY;
 305     case WebLocalizedString::ValidationTypeMismatchForEmailEmptyDomain:
 306       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_EMPTY_DOMAIN;
 307     case WebLocalizedString::ValidationTypeMismatchForEmailEmptyLocal:
 308       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_EMPTY_LOCAL;
 309     case WebLocalizedString::ValidationTypeMismatchForEmailInvalidDomain:
 310       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_INVALID_DOMAIN;
 311     case WebLocalizedString::ValidationTypeMismatchForEmailInvalidDots:
 312       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_INVALID_DOTS;
 313     case WebLocalizedString::ValidationTypeMismatchForEmailInvalidLocal:
 314       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_INVALID_LOCAL;
 315     case WebLocalizedString::ValidationTypeMismatchForEmailNoAtSign:
 316       return IDS_FORM_VALIDATION_TYPE_MISMATCH_EMAIL_NO_AT_SIGN;
 317     case WebLocalizedString::ValidationTypeMismatchForMultipleEmail:
 318       return IDS_FORM_VALIDATION_TYPE_MISMATCH_MULTIPLE_EMAIL;
 319     case WebLocalizedString::ValidationTypeMismatchForURL:
 320       return IDS_FORM_VALIDATION_TYPE_MISMATCH_URL;
 321     case WebLocalizedString::ValidationValueMissing:
 322       return IDS_FORM_VALIDATION_VALUE_MISSING;
 323     case WebLocalizedString::ValidationValueMissingForCheckbox:
 324       return IDS_FORM_VALIDATION_VALUE_MISSING_CHECKBOX;
 325     case WebLocalizedString::ValidationValueMissingForFile:
 326       return IDS_FORM_VALIDATION_VALUE_MISSING_FILE;
 327     case WebLocalizedString::ValidationValueMissingForMultipleFile:
 328       return IDS_FORM_VALIDATION_VALUE_MISSING_MULTIPLE_FILE;
 329     case WebLocalizedString::ValidationValueMissingForRadio:
 330       return IDS_FORM_VALIDATION_VALUE_MISSING_RADIO;
 331     case WebLocalizedString::ValidationValueMissingForSelect:
 332       return IDS_FORM_VALIDATION_VALUE_MISSING_SELECT;
 333     case WebLocalizedString::WeekFormatTemplate:
 334       return IDS_FORM_INPUT_WEEK_TEMPLATE;
 335     case WebLocalizedString::WeekNumberLabel:
 336       return IDS_FORM_WEEK_NUMBER_LABEL;
 337     // This "default:" line exists to avoid compile warnings about enum
 338     // coverage when we add a new symbol to WebLocalizedString.h in WebKit.
 339     // After a planned WebKit patch is landed, we need to add a case statement
 340     // for the added symbol here.
 341     default:
 342       break;
 343   }
 344   return -1;
 345 }
 346
 347 WebKitPlatformSupportImpl::WebKitPlatformSupportImpl()
 348     : main_loop_(base::MessageLoop::current()),
 349       shared_timer_func_(NULL),
 350       shared_timer_fire_time_(0.0),
 351       shared_timer_fire_time_was_set_while_suspended_(false),
 352       shared_timer_suspended_(0) {}
 353
 354 WebKitPlatformSupportImpl::~WebKitPlatformSupportImpl() {
 355 }
 356
 357 WebURLLoader* WebKitPlatformSupportImpl::createURLLoader() {
 358   return new WebURLLoaderImpl(this);
 359 }
 360
 361 WebSocketStreamHandle* WebKitPlatformSupportImpl::createSocketStreamHandle() {
 362   return new WebSocketStreamHandleImpl(this);
 363 }
 364
 365 WebString WebKitPlatformSupportImpl::userAgent(const WebURL& url) {
 366   return WebString::fromUTF8(webkit_glue::GetUserAgent(url));
 367 }
 368
 369 WebData WebKitPlatformSupportImpl::parseDataURL(
 370     const WebURL& url,
 371     WebString& mimetype_out,
 372     WebString& charset_out) {
 373   std::string mime_type, char_set, data;
 374   if (net::DataURL::Parse(url, &mime_type, &char_set, &data)
 375       && net::IsSupportedMimeType(mime_type)) {
 376     mimetype_out = WebString::fromUTF8(mime_type);
 377     charset_out = WebString::fromUTF8(char_set);
 378     return data;
 379   }
 380   return WebData();
 381 }
 382
 383 WebURLError WebKitPlatformSupportImpl::cancelledError(
 384     const WebURL& unreachableURL) const {
 385   return WebURLLoaderImpl::CreateError(unreachableURL, false, net::ERR_ABORTED);
 386 }
 387
 388 void WebKitPlatformSupportImpl::decrementStatsCounter(const char* name) {
 389   base::StatsCounter(name).Decrement();
 390 }
 391
 392 void WebKitPlatformSupportImpl::incrementStatsCounter(const char* name) {
 393   base::StatsCounter(name).Increment();
 394 }
 395
 396 void WebKitPlatformSupportImpl::histogramCustomCounts(
 397     const char* name, int sample, int min, int max, int bucket_count) {
 398   // Copied from histogram macro, but without the static variable caching
 399   // the histogram because name is dynamic.
 400   base::HistogramBase* counter =
 401       base::Histogram::FactoryGet(name, min, max, bucket_count,
 402           base::HistogramBase::kUmaTargetedHistogramFlag);
 403   DCHECK_EQ(name, counter->histogram_name());
 404   counter->Add(sample);
 405 }
 406
 407 void WebKitPlatformSupportImpl::histogramEnumeration(
 408     const char* name, int sample, int boundary_value) {
 409   // Copied from histogram macro, but without the static variable caching
 410   // the histogram because name is dynamic.
 411   base::HistogramBase* counter =
 412       base::LinearHistogram::FactoryGet(name, 1, boundary_value,
 413           boundary_value + 1, base::HistogramBase::kUmaTargetedHistogramFlag);
 414   DCHECK_EQ(name, counter->histogram_name());
 415   counter->Add(sample);
 416 }
 417
 418 void WebKitPlatformSupportImpl::histogramSparse(const char* name, int sample) {
 419   // For sparse histograms, we can use the macro, as it does not incorporate a
 420   // static.
 421   UMA_HISTOGRAM_SPARSE_SLOWLY(name, sample);
 422 }
 423
 424 const unsigned char* WebKitPlatformSupportImpl::getTraceCategoryEnabledFlag(
 425     const char* category_group) {
 426   return TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(category_group);
 427 }
 428
 429 long* WebKitPlatformSupportImpl::getTraceSamplingState(
 430     const unsigned thread_bucket) {
 431   switch (thread_bucket) {
 432     case 0:
 433       return reinterpret_cast<long*>(&TRACE_EVENT_API_THREAD_BUCKET(0));
 434     case 1:
 435       return reinterpret_cast<long*>(&TRACE_EVENT_API_THREAD_BUCKET(1));
 436     case 2:
 437       return reinterpret_cast<long*>(&TRACE_EVENT_API_THREAD_BUCKET(2));
 438     default:
 439       NOTREACHED() << "Unknown thread bucket type.";
 440   }
 441   return NULL;
 442 }
 443
 444 COMPILE_ASSERT(
 445     sizeof(blink::Platform::TraceEventHandle) ==
 446         sizeof(base::debug::TraceEventHandle),
 447     TraceEventHandle_types_must_be_same_size);
 448
 449 blink::Platform::TraceEventHandle WebKitPlatformSupportImpl::addTraceEvent(
 450     char phase,
 451     const unsigned char* category_group_enabled,
 452     const char* name,
 453     unsigned long long id,
 454     int num_args,
 455     const char** arg_names,
 456     const unsigned char* arg_types,
 457     const unsigned long long* arg_values,
 458     unsigned char flags) {
 459   base::debug::TraceEventHandle handle = TRACE_EVENT_API_ADD_TRACE_EVENT(
 460       phase, category_group_enabled, name, id,
 461       num_args, arg_names, arg_types, arg_values, NULL, flags);
 462   blink::Platform::TraceEventHandle result;
 463   memcpy(&result, &handle, sizeof(result));
 464   return result;
 465 }
 466
 467 void WebKitPlatformSupportImpl::updateTraceEventDuration(
 468     const unsigned char* category_group_enabled,
 469     const char* name,
 470     TraceEventHandle handle) {
 471   base::debug::TraceEventHandle traceEventHandle;
 472   memcpy(&traceEventHandle, &handle, sizeof(handle));
 473   TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(
 474       category_group_enabled, name, traceEventHandle);
 475 }
 476
 477 namespace {
 478
 479 WebData loadAudioSpatializationResource(WebKitPlatformSupportImpl* platform,
 480                                         const char* name) {
 481 #ifdef IDR_AUDIO_SPATIALIZATION_COMPOSITE
 482   if (!strcmp(name, "Composite")) {
 483     base::StringPiece resource =
 484         platform->GetDataResource(IDR_AUDIO_SPATIALIZATION_COMPOSITE,
 485                                   ui::SCALE_FACTOR_NONE);
 486     return WebData(resource.data(), resource.size());
 487   }
 488 #endif
 489
 490 #ifdef IDR_AUDIO_SPATIALIZATION_T000_P000
 491   const size_t kExpectedSpatializationNameLength = 31;
 492   if (strlen(name) != kExpectedSpatializationNameLength) {
 493     return WebData();
 494   }
 495
 496   // Extract the azimuth and elevation from the resource name.
 497   int azimuth = 0;
 498   int elevation = 0;
 499   int values_parsed =
 500       sscanf(name, "IRC_Composite_C_R0195_T%3d_P%3d", &azimuth, &elevation);
 501   if (values_parsed != 2) {
 502     return WebData();
 503   }
 504
 505   // The resource index values go through the elevations first, then azimuths.
 506   const int kAngleSpacing = 15;
 507
 508   // 0 <= elevation <= 90 (or 315 <= elevation <= 345)
 509   // in increments of 15 degrees.
 510   int elevation_index =
 511       elevation <= 90 ? elevation / kAngleSpacing :
 512       7 + (elevation - 315) / kAngleSpacing;
 513   bool is_elevation_index_good = 0 <= elevation_index && elevation_index < 10;
 514
 515   // 0 <= azimuth < 360 in increments of 15 degrees.
 516   int azimuth_index = azimuth / kAngleSpacing;
 517   bool is_azimuth_index_good = 0 <= azimuth_index && azimuth_index < 24;
 518
 519   const int kNumberOfElevations = 10;
 520   const int kNumberOfAudioResources = 240;
 521   int resource_index = kNumberOfElevations * azimuth_index + elevation_index;
 522   bool is_resource_index_good = 0 <= resource_index &&
 523       resource_index < kNumberOfAudioResources;
 524
 525   if (is_azimuth_index_good && is_elevation_index_good &&
 526       is_resource_index_good) {
 527     const int kFirstAudioResourceIndex = IDR_AUDIO_SPATIALIZATION_T000_P000;
 528     base::StringPiece resource =
 529         platform->GetDataResource(kFirstAudioResourceIndex + resource_index,
 530                                   ui::SCALE_FACTOR_NONE);
 531     return WebData(resource.data(), resource.size());
 532   }
 533 #endif  // IDR_AUDIO_SPATIALIZATION_T000_P000
 534
 535   NOTREACHED();
 536   return WebData();
 537 }
 538
 539 struct DataResource {
 540   const char* name;
 541   int id;
 542   ui::ScaleFactor scale_factor;
 543 };
 544
 545 const DataResource kDataResources[] = {
 546   { "missingImage", IDR_BROKENIMAGE, ui::SCALE_FACTOR_100P },
 547   { "missingImage@2x", IDR_BROKENIMAGE, ui::SCALE_FACTOR_200P },
 548   { "mediaplayerPause", IDR_MEDIAPLAYER_PAUSE_BUTTON, ui::SCALE_FACTOR_100P },
 549   { "mediaplayerPauseHover",
 550     IDR_MEDIAPLAYER_PAUSE_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 551   { "mediaplayerPauseDown",
 552     IDR_MEDIAPLAYER_PAUSE_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 553   { "mediaplayerPlay", IDR_MEDIAPLAYER_PLAY_BUTTON, ui::SCALE_FACTOR_100P },
 554   { "mediaplayerPlayHover",
 555     IDR_MEDIAPLAYER_PLAY_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 556   { "mediaplayerPlayDown",
 557     IDR_MEDIAPLAYER_PLAY_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 558   { "mediaplayerPlayDisabled",
 559     IDR_MEDIAPLAYER_PLAY_BUTTON_DISABLED, ui::SCALE_FACTOR_100P },
 560   { "mediaplayerSoundLevel3",
 561     IDR_MEDIAPLAYER_SOUND_LEVEL3_BUTTON, ui::SCALE_FACTOR_100P },
 562   { "mediaplayerSoundLevel3Hover",
 563     IDR_MEDIAPLAYER_SOUND_LEVEL3_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 564   { "mediaplayerSoundLevel3Down",
 565     IDR_MEDIAPLAYER_SOUND_LEVEL3_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 566   { "mediaplayerSoundLevel2",
 567     IDR_MEDIAPLAYER_SOUND_LEVEL2_BUTTON, ui::SCALE_FACTOR_100P },
 568   { "mediaplayerSoundLevel2Hover",
 569     IDR_MEDIAPLAYER_SOUND_LEVEL2_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 570   { "mediaplayerSoundLevel2Down",
 571     IDR_MEDIAPLAYER_SOUND_LEVEL2_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 572   { "mediaplayerSoundLevel1",
 573     IDR_MEDIAPLAYER_SOUND_LEVEL1_BUTTON, ui::SCALE_FACTOR_100P },
 574   { "mediaplayerSoundLevel1Hover",
 575     IDR_MEDIAPLAYER_SOUND_LEVEL1_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 576   { "mediaplayerSoundLevel1Down",
 577     IDR_MEDIAPLAYER_SOUND_LEVEL1_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 578   { "mediaplayerSoundLevel0",
 579     IDR_MEDIAPLAYER_SOUND_LEVEL0_BUTTON, ui::SCALE_FACTOR_100P },
 580   { "mediaplayerSoundLevel0Hover",
 581     IDR_MEDIAPLAYER_SOUND_LEVEL0_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 582   { "mediaplayerSoundLevel0Down",
 583     IDR_MEDIAPLAYER_SOUND_LEVEL0_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 584   { "mediaplayerSoundDisabled",
 585     IDR_MEDIAPLAYER_SOUND_DISABLED, ui::SCALE_FACTOR_100P },
 586   { "mediaplayerSliderThumb",
 587     IDR_MEDIAPLAYER_SLIDER_THUMB, ui::SCALE_FACTOR_100P },
 588   { "mediaplayerSliderThumbHover",
 589     IDR_MEDIAPLAYER_SLIDER_THUMB_HOVER, ui::SCALE_FACTOR_100P },
 590   { "mediaplayerSliderThumbDown",
 591     IDR_MEDIAPLAYER_SLIDER_THUMB_DOWN, ui::SCALE_FACTOR_100P },
 592   { "mediaplayerVolumeSliderThumb",
 593     IDR_MEDIAPLAYER_VOLUME_SLIDER_THUMB, ui::SCALE_FACTOR_100P },
 594   { "mediaplayerVolumeSliderThumbHover",
 595     IDR_MEDIAPLAYER_VOLUME_SLIDER_THUMB_HOVER, ui::SCALE_FACTOR_100P },
 596   { "mediaplayerVolumeSliderThumbDown",
 597     IDR_MEDIAPLAYER_VOLUME_SLIDER_THUMB_DOWN, ui::SCALE_FACTOR_100P },
 598   { "mediaplayerVolumeSliderThumbDisabled",
 599     IDR_MEDIAPLAYER_VOLUME_SLIDER_THUMB_DISABLED, ui::SCALE_FACTOR_100P },
 600   { "mediaplayerClosedCaption",
 601     IDR_MEDIAPLAYER_CLOSEDCAPTION_BUTTON, ui::SCALE_FACTOR_100P },
 602   { "mediaplayerClosedCaptionHover",
 603     IDR_MEDIAPLAYER_CLOSEDCAPTION_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 604   { "mediaplayerClosedCaptionDown",
 605     IDR_MEDIAPLAYER_CLOSEDCAPTION_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 606   { "mediaplayerClosedCaptionDisabled",
 607     IDR_MEDIAPLAYER_CLOSEDCAPTION_BUTTON_DISABLED, ui::SCALE_FACTOR_100P },
 608   { "mediaplayerFullscreen",
 609     IDR_MEDIAPLAYER_FULLSCREEN_BUTTON, ui::SCALE_FACTOR_100P },
 610   { "mediaplayerFullscreenHover",
 611     IDR_MEDIAPLAYER_FULLSCREEN_BUTTON_HOVER, ui::SCALE_FACTOR_100P },
 612   { "mediaplayerFullscreenDown",
 613     IDR_MEDIAPLAYER_FULLSCREEN_BUTTON_DOWN, ui::SCALE_FACTOR_100P },
 614   { "mediaplayerFullscreenDisabled",
 615     IDR_MEDIAPLAYER_FULLSCREEN_BUTTON_DISABLED, ui::SCALE_FACTOR_100P },
 616 #if defined(OS_ANDROID)
 617   { "mediaplayerOverlayPlay",
 618     IDR_MEDIAPLAYER_OVERLAY_PLAY_BUTTON, ui::SCALE_FACTOR_100P },
 619 #endif
 620 #if defined(OS_MACOSX)
 621   { "overhangPattern", IDR_OVERHANG_PATTERN, ui::SCALE_FACTOR_100P },
 622   { "overhangShadow", IDR_OVERHANG_SHADOW, ui::SCALE_FACTOR_100P },
 623 #endif
 624   { "panIcon", IDR_PAN_SCROLL_ICON, ui::SCALE_FACTOR_100P },
 625   { "searchCancel", IDR_SEARCH_CANCEL, ui::SCALE_FACTOR_100P },
 626   { "searchCancelPressed", IDR_SEARCH_CANCEL_PRESSED, ui::SCALE_FACTOR_100P },
 627   { "searchMagnifier", IDR_SEARCH_MAGNIFIER, ui::SCALE_FACTOR_100P },
 628   { "searchMagnifierResults",
 629     IDR_SEARCH_MAGNIFIER_RESULTS, ui::SCALE_FACTOR_100P },
 630   { "textAreaResizeCorner", IDR_TEXTAREA_RESIZER, ui::SCALE_FACTOR_100P },
 631   { "textAreaResizeCorner@2x", IDR_TEXTAREA_RESIZER, ui::SCALE_FACTOR_200P },
 632   { "inputSpeech", IDR_INPUT_SPEECH, ui::SCALE_FACTOR_100P },
 633   { "inputSpeechRecording", IDR_INPUT_SPEECH_RECORDING, ui::SCALE_FACTOR_100P },
 634   { "inputSpeechWaiting", IDR_INPUT_SPEECH_WAITING, ui::SCALE_FACTOR_100P },
 635   { "americanExpressCC", IDR_AUTOFILL_CC_AMEX, ui::SCALE_FACTOR_100P },
 636   { "dinersCC", IDR_AUTOFILL_CC_DINERS, ui::SCALE_FACTOR_100P },
 637   { "discoverCC", IDR_AUTOFILL_CC_DISCOVER, ui::SCALE_FACTOR_100P },
 638   { "genericCC", IDR_AUTOFILL_CC_GENERIC, ui::SCALE_FACTOR_100P },
 639   { "jcbCC", IDR_AUTOFILL_CC_JCB, ui::SCALE_FACTOR_100P },
 640   { "masterCardCC", IDR_AUTOFILL_CC_MASTERCARD, ui::SCALE_FACTOR_100P },
 641   { "visaCC", IDR_AUTOFILL_CC_VISA, ui::SCALE_FACTOR_100P },
 642   { "generatePassword", IDR_PASSWORD_GENERATION_ICON, ui::SCALE_FACTOR_100P },
 643   { "generatePasswordHover",
 644     IDR_PASSWORD_GENERATION_ICON_HOVER, ui::SCALE_FACTOR_100P },
 645   { "syntheticTouchCursor",
 646     IDR_SYNTHETIC_TOUCH_CURSOR, ui::SCALE_FACTOR_100P },
 647 };
 648
 649 }  // namespace
 650
 651 WebData WebKitPlatformSupportImpl::loadResource(const char* name) {
 652   // Some clients will call into this method with an empty |name| when they have
 653   // optional resources.  For example, the PopupMenuChromium code can have icons
 654   // for some Autofill items but not for others.
 655   if (!strlen(name))
 656     return WebData();
 657
 658   // Check the name prefix to see if it's an audio resource.
 659   if (StartsWithASCII(name, "IRC_Composite", true) ||
 660       StartsWithASCII(name, "Composite", true))
 661     return loadAudioSpatializationResource(this, name);
 662
 663   // TODO(flackr): We should use a better than linear search here, a trie would
 664   // be ideal.
 665   for (size_t i = 0; i < arraysize(kDataResources); ++i) {
 666     if (!strcmp(name, kDataResources[i].name)) {
 667       base::StringPiece resource =
 668           GetDataResource(kDataResources[i].id,
 669                           kDataResources[i].scale_factor);
 670       return WebData(resource.data(), resource.size());
 671     }
 672   }
 673
 674   NOTREACHED() << "Unknown image resource " << name;
 675   return WebData();
 676 }
 677
 678 WebString WebKitPlatformSupportImpl::queryLocalizedString(
 679     WebLocalizedString::Name name) {
 680   int message_id = ToMessageID(name);
 681   if (message_id < 0)
 682     return WebString();
 683   return GetLocalizedString(message_id);
 684 }
 685
 686 WebString WebKitPlatformSupportImpl::queryLocalizedString(
 687     WebLocalizedString::Name name, int numeric_value) {
 688   return queryLocalizedString(name, base::IntToString16(numeric_value));
 689 }
 690
 691 WebString WebKitPlatformSupportImpl::queryLocalizedString(
 692     WebLocalizedString::Name name, const WebString& value) {
 693   int message_id = ToMessageID(name);
 694   if (message_id < 0)
 695     return WebString();
 696   return ReplaceStringPlaceholders(GetLocalizedString(message_id), value, NULL);
 697 }
 698
 699 WebString WebKitPlatformSupportImpl::queryLocalizedString(
 700     WebLocalizedString::Name name,
 701     const WebString& value1,
 702     const WebString& value2) {
 703   int message_id = ToMessageID(name);
 704   if (message_id < 0)
 705     return WebString();
 706   std::vector<base::string16> values;
 707   values.reserve(2);
 708   values.push_back(value1);
 709   values.push_back(value2);
 710   return ReplaceStringPlaceholders(
 711       GetLocalizedString(message_id), values, NULL);
 712 }
 713
 714 double WebKitPlatformSupportImpl::currentTime() {
 715   return base::Time::Now().ToDoubleT();
 716 }
 717
 718 double WebKitPlatformSupportImpl::monotonicallyIncreasingTime() {
 719   return base::TimeTicks::Now().ToInternalValue() /
 720       static_cast<double>(base::Time::kMicrosecondsPerSecond);
 721 }
 722
 723 void WebKitPlatformSupportImpl::cryptographicallyRandomValues(
 724     unsigned char* buffer, size_t length) {
 725   base::RandBytes(buffer, length);
 726 }
 727
 728 void WebKitPlatformSupportImpl::setSharedTimerFiredFunction(void (*func)()) {
 729   shared_timer_func_ = func;
 730 }
 731
 732 void WebKitPlatformSupportImpl::setSharedTimerFireInterval(
 733     double interval_seconds) {
 734   shared_timer_fire_time_ = interval_seconds + monotonicallyIncreasingTime();
 735   if (shared_timer_suspended_) {
 736     shared_timer_fire_time_was_set_while_suspended_ = true;
 737     return;
 738   }
 739
 740   // By converting between double and int64 representation, we run the risk
 741   // of losing precision due to rounding errors. Performing computations in
 742   // microseconds reduces this risk somewhat. But there still is the potential
 743   // of us computing a fire time for the timer that is shorter than what we
 744   // need.
 745   // As the event loop will check event deadlines prior to actually firing
 746   // them, there is a risk of needlessly rescheduling events and of
 747   // needlessly looping if sleep times are too short even by small amounts.
 748   // This results in measurable performance degradation unless we use ceil() to
 749   // always round up the sleep times.
 750   int64 interval = static_cast<int64>(
 751       ceil(interval_seconds * base::Time::kMillisecondsPerSecond)
 752       * base::Time::kMicrosecondsPerMillisecond);
 753
 754   if (interval < 0)
 755     interval = 0;
 756
 757   shared_timer_.Stop();
 758   shared_timer_.Start(FROM_HERE, base::TimeDelta::FromMicroseconds(interval),
 759                       this, &WebKitPlatformSupportImpl::DoTimeout);
 760   OnStartSharedTimer(base::TimeDelta::FromMicroseconds(interval));
 761 }
 762
 763 void WebKitPlatformSupportImpl::stopSharedTimer() {
 764   shared_timer_.Stop();
 765 }
 766
 767 void WebKitPlatformSupportImpl::callOnMainThread(
 768     void (*func)(void*), void* context) {
 769   main_loop_->PostTask(FROM_HERE, base::Bind(func, context));
 770 }
 771
 772 base::PlatformFile WebKitPlatformSupportImpl::databaseOpenFile(
 773     const blink::WebString& vfs_file_name, int desired_flags) {
 774   return base::kInvalidPlatformFileValue;
 775 }
 776
 777 int WebKitPlatformSupportImpl::databaseDeleteFile(
 778     const blink::WebString& vfs_file_name, bool sync_dir) {
 779   return -1;
 780 }
 781
 782 long WebKitPlatformSupportImpl::databaseGetFileAttributes(
 783     const blink::WebString& vfs_file_name) {
 784   return 0;
 785 }
 786
 787 long long WebKitPlatformSupportImpl::databaseGetFileSize(
 788     const blink::WebString& vfs_file_name) {
 789   return 0;
 790 }
 791
 792 long long WebKitPlatformSupportImpl::databaseGetSpaceAvailableForOrigin(
 793     const blink::WebString& origin_identifier) {
 794   return 0;
 795 }
 796
 797 blink::WebString WebKitPlatformSupportImpl::signedPublicKeyAndChallengeString(
 798     unsigned key_size_index,
 799     const blink::WebString& challenge,
 800     const blink::WebURL& url) {
 801   return blink::WebString("");
 802 }
 803
 804 static scoped_ptr<base::ProcessMetrics> CurrentProcessMetrics() {
 805   using base::ProcessMetrics;
 806 #if defined(OS_MACOSX)
 807   return scoped_ptr<ProcessMetrics>(
 808       // The default port provider is sufficient to get data for the current
 809       // process.
 810       ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle(),
 811                                            NULL));
 812 #else
 813   return scoped_ptr<ProcessMetrics>(
 814       ProcessMetrics::CreateProcessMetrics(base::GetCurrentProcessHandle()));
 815 #endif
 816 }
 817
 818 static size_t getMemoryUsageMB(bool bypass_cache) {
 819   size_t current_mem_usage = 0;
 820   MemoryUsageCache* mem_usage_cache_singleton = MemoryUsageCache::GetInstance();
 821   if (!bypass_cache &&
 822       mem_usage_cache_singleton->IsCachedValueValid(&current_mem_usage))
 823     return current_mem_usage;
 824
 825   current_mem_usage = MemoryUsageKB() >> 10;
 826   mem_usage_cache_singleton->SetMemoryValue(current_mem_usage);
 827   return current_mem_usage;
 828 }
 829
 830 size_t WebKitPlatformSupportImpl::memoryUsageMB() {
 831   return getMemoryUsageMB(false);
 832 }
 833
 834 size_t WebKitPlatformSupportImpl::actualMemoryUsageMB() {
 835   return getMemoryUsageMB(true);
 836 }
 837
 838 size_t WebKitPlatformSupportImpl::physicalMemoryMB() {
 839   return static_cast<size_t>(base::SysInfo::AmountOfPhysicalMemoryMB());
 840 }
 841
 842 size_t WebKitPlatformSupportImpl::numberOfProcessors() {
 843   return static_cast<size_t>(base::SysInfo::NumberOfProcessors());
 844 }
 845
 846 void WebKitPlatformSupportImpl::startHeapProfiling(
 847   const blink::WebString& prefix) {
 848   // FIXME(morrita): Make this built on windows.
 849 #if !defined(NO_TCMALLOC) && defined(USE_TCMALLOC) && !defined(OS_WIN)
 850   HeapProfilerStart(prefix.utf8().data());
 851 #endif
 852 }
 853
 854 void WebKitPlatformSupportImpl::stopHeapProfiling() {
 855 #if !defined(NO_TCMALLOC) && defined(USE_TCMALLOC) && !defined(OS_WIN)
 856   HeapProfilerStop();
 857 #endif
 858 }
 859
 860 void WebKitPlatformSupportImpl::dumpHeapProfiling(
 861   const blink::WebString& reason) {
 862 #if !defined(NO_TCMALLOC) && defined(USE_TCMALLOC) && !defined(OS_WIN)
 863   HeapProfilerDump(reason.utf8().data());
 864 #endif
 865 }
 866
 867 WebString WebKitPlatformSupportImpl::getHeapProfile() {
 868 #if !defined(NO_TCMALLOC) && defined(USE_TCMALLOC) && !defined(OS_WIN)
 869   char* data = GetHeapProfile();
 870   WebString result = WebString::fromUTF8(std::string(data));
 871   free(data);
 872   return result;
 873 #else
 874   return WebString();
 875 #endif
 876 }
 877
 878 bool WebKitPlatformSupportImpl::processMemorySizesInBytes(
 879     size_t* private_bytes,
 880     size_t* shared_bytes) {
 881   return CurrentProcessMetrics()->GetMemoryBytes(private_bytes, shared_bytes);
 882 }
 883
 884 bool WebKitPlatformSupportImpl::memoryAllocatorWasteInBytes(size_t* size) {
 885   return base::allocator::GetAllocatorWasteSize(size);
 886 }
 887
 888 size_t WebKitPlatformSupportImpl::maxDecodedImageBytes() {
 889 #if defined(OS_ANDROID)
 890   if (base::android::SysUtils::IsLowEndDevice()) {
 891     // Limit image decoded size to 3M pixels on low end devices.
 892     // 4 is maximum number of bytes per pixel.
 893     return 3 * 1024 * 1024 * 4;
 894   }
 895   // For other devices, limit decoded image size based on the amount of physical
 896   // memory. For a device with 2GB physical memory the limit is 16M pixels.
 897   return base::SysInfo::AmountOfPhysicalMemory() / 32;
 898 #else
 899   return noDecodedImageByteLimit;
 900 #endif
 901 }
 902
 903 void WebKitPlatformSupportImpl::SuspendSharedTimer() {
 904   ++shared_timer_suspended_;
 905 }
 906
 907 void WebKitPlatformSupportImpl::ResumeSharedTimer() {
 908   // The shared timer may have fired or been adjusted while we were suspended.
 909   if (--shared_timer_suspended_ == 0 &&
 910       (!shared_timer_.IsRunning() ||
 911        shared_timer_fire_time_was_set_while_suspended_)) {
 912     shared_timer_fire_time_was_set_while_suspended_ = false;
 913     setSharedTimerFireInterval(
 914         shared_timer_fire_time_ - monotonicallyIncreasingTime());
 915   }
 916 }
 917
 918 }  // namespace webkit_glue