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