Add full support for filesystem URLs.

Add full support for filesystem URLs.
https://bugs.webkit.org/show_bug.cgi?id=75049

Reviewed by Adam Barth.

No new tests; existing layout tests cover the basic functionality, and
the new functionality won't be there until Chromium adds it.  This patch
merely enables that, without changing behavior.

Source/WebCore:

* fileapi/EntryBase.cpp:
(WebCore::EntryBase::toURL): Add missing escaping of URL path.

* page/SecurityOrigin.cpp:
(WebCore::extractInnerURL): Use innerURL member, if it's populated.

* platform/KURL.h:
(WebCore::KURL::innerURL): Add innerURL member.

* platform/KURLGoogle.cpp:
(WebCore::KURLGooglePrivate::KURLGooglePrivate):
(WebCore::KURLGooglePrivate::operator=):
Add copy constructor and operator=, which are now needed since
m_innerURL needs special handling.
(WebCore::KURLGooglePrivate::setUtf8):
(WebCore::KURLGooglePrivate::setAscii):
Add calls to initInnerURL.
(WebCore::KURLGooglePrivate::initInnerURL):
Add method to init/copy m_innerURL.
(WebCore::KURLGooglePrivate::copyTo):
Handle m_innerURL during copies.
(WebCore::encodeWithURLEscapeSequences):
Unescape %2F ['/'] in paths; it's much more readable, and it's safe.

* platform/KURLGooglePrivate.h:
(WebCore::KURLGooglePrivate::innerURL): Add accessor for new m_innerURL.

Source/WebKit/chromium:

* tests/KURLTest.cpp:
TEST(KURLTest, Encode): Update expectation that '/' sails through unescaped.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@105930 268f45cc-cd09-0410-ab3c-d52691b4dbfc