Reland "Add new latency_info for tracking browser composite time."

content/browser/renderer_host/compositor_impl_android.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/compositor_impl_android.h"
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
 
 #include "base/android/jni_android.h"
@@ skipping 63 matching lines @@
         swap_buffers_completion_callback_(
             base::Bind(&OutputSurfaceWithoutParent::OnSwapBuffersCompleted,
                        base::Unretained(this))) {
     capabilities_.adjust_deadline_for_parent = false;
     capabilities_.max_frames_pending = 2;
     compositor_impl_ = compositor_impl;
     main_thread_ = base::MessageLoopProxy::current();
   }
 
   virtual void SwapBuffers(cc::CompositorFrame* frame) override {
+    for (auto& latency : frame->metadata.latency_info) {
+      latency.AddLatencyNumber(
+          ui::INPUT_EVENT_BROWSER_SWAP_BUFFER_COMPONENT, 0, 0);

[jdduke (slow), 2015/01/06 16:01:43]

Hmm, I actually don't see this component used anywhere. The deadline estimation
only uses BROWSER_COMPOSITE_COMPONENT and GPU_SWAP_BUFFER_COMPONENT. Can we get
rid of this?

+    }
+
     GetCommandBufferProxy()->SetLatencyInfo(frame->metadata.latency_info);
     DCHECK(frame->gl_frame_data->sub_buffer_rect ==
            gfx::Rect(frame->gl_frame_data->size));
     context_provider_->ContextSupport()->Swap();
     client_->DidSwapBuffers();
   }
 
   virtual bool BindToClient(cc::OutputSurfaceClient* client) override {
     if (!OutputSurface::BindToClient(client))
       return false;
@@ skipping 601 matching lines @@
 
 void CompositorImpl::SetNeedsAnimate() {
   needs_animate_ = true;
   if (!host_)
     return;
 
   host_->SetNeedsAnimate();
 }
 
 }  // namespace content