Reland: Use a shared thread for media operations (round 3).

webkit/support/webkit_support.cc

Index: webkit/support/webkit_support.cc
diff --git a/webkit/support/webkit_support.cc b/webkit/support/webkit_support.cc
index ba537a8513e52bf80d9bbef7ad6912f7202383ab..51997ececc4706ee7102797575312c3be6e45c9a 100644
--- a/webkit/support/webkit_support.cc
+++ b/webkit/support/webkit_support.cc
@@ -206,6 +206,14 @@ class TestEnvironment {
   }
 #endif
 
+  scoped_refptr<base::MessageLoopProxy> GetMediaThreadMessageLoopProxy() {
+    if (!media_thread_) {
+      media_thread_.reset(new base::Thread("Media"));
+      CHECK(media_thread_->Start());
+    }
+    return media_thread_->message_loop_proxy();
+  }
+
  private:
   // Data member at_exit_manager_ will take the ownership of the input
   // AtExitManager and manage its lifecycle.
@@ -213,6 +221,8 @@ class TestEnvironment {
   scoped_ptr<MessageLoopType> main_message_loop_;
   scoped_ptr<TestWebKitPlatformSupport> webkit_platform_support_;
 
+  scoped_ptr<base::Thread> media_thread_;
+
 #if defined(OS_ANDROID)
   base::FilePath mock_current_directory_;
 #endif
@@ -404,6 +414,7 @@ WebKit::WebMediaPlayer* CreateMediaPlayer(
   return NULL;
 #else
   webkit_media::WebMediaPlayerParams params(
+      test_environment->GetMediaThreadMessageLoopProxy(),
       NULL, NULL, new media::MediaLog());
   return new webkit_media::WebMediaPlayerImpl(
       frame,