Deliver IPC messages together with SwapCompositorFrame

content/browser/renderer_host/render_widget_host_impl.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/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 1454 matching lines @@
   // This trace event is used in
   // chrome/browser/extensions/api/cast_streaming/performance_test.cc
   UNSHIPPED_TRACE_EVENT0("test_fps",
                          TRACE_DISABLED_BY_DEFAULT("OnSwapCompositorFrame"));
   ViewHostMsg_SwapCompositorFrame::Param param;
   if (!ViewHostMsg_SwapCompositorFrame::Read(&message, &param))
     return false;
   scoped_ptr<cc::CompositorFrame> frame(new cc::CompositorFrame);
   uint32 output_surface_id = param.a;
   param.b.AssignTo(frame.get());
+  std::vector<IPC::Message> messages_to_deliver_with_frame;
+  messages_to_deliver_with_frame.swap(param.c);
+
+  for (std::vector<IPC::Message>::const_iterator i =
+           messages_to_deliver_with_frame.begin();
+       i != messages_to_deliver_with_frame.end();
+       ++i) {
+    GetProcess()->OnMessageReceived(*i);
+  }
+  messages_to_deliver_with_frame.clear();

[piman, 2014/05/20 19:54:05]

Do you need these to be delivered before the OnSwapCompositorFrame?
For the other things I would like to use this for (e.g. the UpdateRect message),
it would make more sense to deliver them after the frame.
It would also slightly alleviate re-entrency concerns if it's at the end of the
method, for example since these messages could be ViewHostMsg_Close or
ViewHostMsg_RenderProcessGone which would end up deleting |this|. For that
reason too, you may want to grab the RenderProcessHost before the loop by the
way (the RPH deletes itself with a DeleteSoon, so there is no risk of it going
away in the loop).

[mkosiba (inactive), 2014/05/22 17:40:24]

nope.
Those are some good points. I'll move the code to the bottom of the method.

 
   for (size_t i = 0; i < frame->metadata.latency_info.size(); i++)
     AddLatencyInfoComponentIds(&frame->metadata.latency_info[i]);
 
   input_router_->OnViewUpdated(
       GetInputRouterViewFlagsFromCompositorFrameMetadata(frame->metadata));
 
   if (view_) {
     view_->OnSwapCompositorFrame(output_surface_id, frame.Pass());
     view_->DidReceiveRendererFrame();
@@ skipping 835 matching lines @@
   }
 }
 
 SkBitmap::Config RenderWidgetHostImpl::PreferredReadbackFormat() {
   if (view_)
     return view_->PreferredReadbackFormat();
   return SkBitmap::kARGB_8888_Config;
 }
 
 }  // namespace content