src/chrome/renderer/prerender/prerender_media_load_deferrer.cc

   1 // Copyright 2013 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 "chrome/renderer/prerender/prerender_media_load_deferrer.h"
   6
   7 #include "base/callback_helpers.h"
   8 #include "chrome/common/prerender_messages.h"
   9 #include "content/public/renderer/render_view.h"
  10
  11 namespace prerender {
  12
  13 PrerenderMediaLoadDeferrer::PrerenderMediaLoadDeferrer(
  14     content::RenderView* render_view,
  15     const base::Closure& closure)
  16     : RenderViewObserver(render_view),
  17       is_prerendering_(true),
  18       continue_loading_cb_(closure) {
  19   DCHECK(!continue_loading_cb_.is_null());
  20 }
  21
  22 PrerenderMediaLoadDeferrer::~PrerenderMediaLoadDeferrer() {}
  23
  24 bool PrerenderMediaLoadDeferrer::OnMessageReceived(
  25     const IPC::Message& message) {
  26   IPC_BEGIN_MESSAGE_MAP(PrerenderMediaLoadDeferrer, message)
  27     IPC_MESSAGE_HANDLER(PrerenderMsg_SetIsPrerendering, OnSetIsPrerendering)
  28   IPC_END_MESSAGE_MAP()
  29
  30   return false;
  31 }
  32
  33 void PrerenderMediaLoadDeferrer::OnSetIsPrerendering(bool is_prerendering) {
  34   // Prerendering can only be enabled prior to a RenderView's first
  35   // navigation, so no PrerenderMediaLoadDeferrer should see the notification
  36   // that enables prerendering.
  37   DCHECK(!is_prerendering);
  38   if (!is_prerendering_ || is_prerendering)
  39     return;
  40
  41   is_prerendering_ = false;
  42   base::ResetAndReturn(&continue_loading_cb_).Run();
  43 }
  44
  45 }  // namespace prerender