Use observer pattern instead of sniffing SwapCompositorFrame IPC

content/public/test/browser_test_utils.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/public/test/browser_test_utils.h"
 
 #include <stddef.h>
 #include <tuple>
 #include <utility>
 
@@ skipping 1515 matching lines @@
   return false;
 }
 
 bool RequestFrame(WebContents* web_contents) {
   DCHECK(web_contents);
   return RenderWidgetHostImpl::From(
              web_contents->GetRenderViewHost()->GetWidget())
       ->ScheduleComposite();
 }
 
-FrameWatcher::FrameWatcher() : MessageFilter(), frames_to_wait_(0) {}
+FrameWatcher::FrameWatcher() = default;
 
-FrameWatcher::~FrameWatcher() {
-}
+FrameWatcher::FrameWatcher(WebContents* web_contents)
+    : WebContentsObserver(web_contents) {}
 
-void FrameWatcher::ReceivedFrameSwap(cc::CompositorFrameMetadata metadata) {
-  --frames_to_wait_;
-  last_metadata_ = std::move(metadata);
-  if (frames_to_wait_ == 0)
-    quit_.Run();
-}
-
-bool FrameWatcher::OnMessageReceived(const IPC::Message& message) {
-  if (message.type() == ViewHostMsg_SwapCompositorFrame::ID) {
-    ViewHostMsg_SwapCompositorFrame::Param param;
-    if (!ViewHostMsg_SwapCompositorFrame::Read(&message, &param))
-      return false;
-    cc::CompositorFrame frame(std::move(std::get<2>(param)));
-
-    BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
-        base::Bind(&FrameWatcher::ReceivedFrameSwap, this,
-                   base::Passed(std::move(frame.metadata))));
-  }
-  return false;
-}
-
-void FrameWatcher::AttachTo(WebContents* web_contents) {
-  DCHECK(web_contents);
-  RenderWidgetHostImpl* widget_host = RenderWidgetHostImpl::From(
-      web_contents->GetRenderViewHost()->GetWidget());
-  widget_host->GetProcess()->GetChannel()->AddFilter(this);
-}
+FrameWatcher::~FrameWatcher() = default;
 
 void FrameWatcher::WaitFrames(int frames_to_wait) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (frames_to_wait <= 0)
     return;
   base::RunLoop run_loop;
   base::AutoReset<base::Closure> reset_quit(&quit_, run_loop.QuitClosure());
   base::AutoReset<int> reset_frames_to_wait(&frames_to_wait_, frames_to_wait);
   run_loop.Run();
 }
 
 const cc::CompositorFrameMetadata& FrameWatcher::LastMetadata() {
-  return last_metadata_;
+  return RenderWidgetHostImpl::From(
+             web_contents()->GetRenderViewHost()->GetWidget())
+      ->last_frame_metadata();
+}
+
+void FrameWatcher::DidReceiveCompositorFrame() {
+  --frames_to_wait_;
+  if (frames_to_wait_ == 0)
+    quit_.Run();
 }
 
 MainThreadFrameObserver::MainThreadFrameObserver(
     RenderWidgetHost* render_widget_host)
     : render_widget_host_(render_widget_host),
       routing_id_(render_widget_host_->GetProcess()->GetNextRoutingID()) {
   // TODO(lfg): We should look into adding a way to observe RenderWidgetHost
   // messages similarly to what WebContentsObserver can do with RFH and RVW.
   render_widget_host_->GetProcess()->AddRoute(routing_id_, this);
 }
@@ skipping 390 matching lines @@
                                  bool user_gesture,
                                  bool last_unlocked_by_target,
                                  bool privileged) {
   IPC::IpcSecurityTestUtil::PwnMessageReceived(
       process->GetChannel(),
       ViewHostMsg_LockMouse(routing_id, user_gesture, last_unlocked_by_target,
                             privileged));
 }
 
 }  // namespace content