Remove some LatencyInfo merging code path

content/browser/aura/software_browser_compositor_output_surface.cc

 // Copyright 2013 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/aura/software_browser_compositor_output_surface.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
 #include "base/time/time.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 17 matching lines @@
                                      output_surface_map,
                                      compositor_message_loop,
                                      compositor),
       output_surface_proxy_(surface_proxy) {}
 
 SoftwareBrowserCompositorOutputSurface::
     ~SoftwareBrowserCompositorOutputSurface() {}
 
 void SoftwareBrowserCompositorOutputSurface::SwapBuffers(
     cc::CompositorFrame* frame) {
-  ui::LatencyInfo latency_info = frame->metadata.latency_info;
-  latency_info.AddLatencyNumber(
-      ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT, 0, 0);
-
-  base::MessageLoop::current()->PostTask(
-      FROM_HERE,
-      base::Bind(
-          &RenderWidgetHostImpl::CompositorFrameDrawn,
-          latency_info));
+  // TODO(miletus) : Convert RenderWidgetHostImpl::CompositorFrameDrawn() to
+  // take std::vector<ui::LatencyInfo> directly so we only post the task once.

[danakj, 2013/12/20 19:27:37]

One question here, should we merge the LatencyInfo here and post once instead of
posting a bunch of times? That seems like it would match the expectations of the
old code which isn't transitioned yet. Not a big deal either way probably?

[Yufeng Shen (Slow to review), 2013/12/20 19:36:32]

It depends on what CompositorFrameDrawn() does with the the LatencyInfo.
CompositorFrameDrawn() does UMA/Telemetry metrics computation on the
LatencyInfo, which is broken currently anyway while I am doing the overhaul, so
it does not really matter.

+  for (size_t i = 0; i < frame->metadata.latency_info.size(); i++) {
+    frame->metadata.latency_info[i].AddLatencyNumber(
+        ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT, 0, 0);
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE,
+        base::Bind(
+            &RenderWidgetHostImpl::CompositorFrameDrawn,
+            frame->metadata.latency_info[i]));
+  }
 
   gfx::VSyncProvider* vsync_provider = software_device()->GetVSyncProvider();
   if (vsync_provider) {
     vsync_provider->GetVSyncParameters(
         base::Bind(&BrowserCompositorOutputSurfaceProxy::
                         OnUpdateVSyncParametersOnCompositorThread,
                    output_surface_proxy_,
                    surface_id_));
   }
 }
 
 }  // namespace content