Read compositor VSync information from platform, when possible

content/browser/compositor/browser_compositor_output_surface.cc

 // Copyright 2014 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/compositor/browser_compositor_output_surface.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/location.h"
-#include "base/message_loop/message_loop_proxy.h"
 #include "base/strings/string_number_conversions.h"
 #include "content/browser/compositor/reflector_impl.h"
 #include "content/common/gpu/client/context_provider_command_buffer.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_switches.h"
 
 namespace content {
 
 BrowserCompositorOutputSurface::BrowserCompositorOutputSurface(
     const scoped_refptr<ContextProviderCommandBuffer>& context_provider,
     int surface_id,
     IDMap<BrowserCompositorOutputSurface>* output_surface_map,
-    base::MessageLoopProxy* compositor_message_loop,
-    base::WeakPtr<ui::Compositor> compositor)
+    ui::Compositor* compositor)

[piman, 2014/02/04 04:51:01]

nit: pass in the vsync_manager() to the constructor, to make it explicit in the
interface that we're not keeping a reference to the Compositor (which lives on
the UI thread) on the compositor thread.

[sheu, 2014/02/04 22:01:45]

I was under the impression that passing a raw pointer makes this kind of
implication in Chrome-land.  But passing vsync_manager() is probably better
anyhow.

Done.

     : OutputSurface(context_provider),
       surface_id_(surface_id),
       output_surface_map_(output_surface_map),
-      compositor_message_loop_(compositor_message_loop),
-      compositor_(compositor) {
+      vsync_manager_(compositor->vsync_manager()) {
   Initialize();
 }
 
 BrowserCompositorOutputSurface::BrowserCompositorOutputSurface(
     scoped_ptr<cc::SoftwareOutputDevice> software_device,
     int surface_id,
     IDMap<BrowserCompositorOutputSurface>* output_surface_map,
-    base::MessageLoopProxy* compositor_message_loop,
-    base::WeakPtr<ui::Compositor> compositor)
+    ui::Compositor* compositor)
     : OutputSurface(software_device.Pass()),
       surface_id_(surface_id),
       output_surface_map_(output_surface_map),
-      compositor_message_loop_(compositor_message_loop),
-      compositor_(compositor) {
+      vsync_manager_(compositor->vsync_manager()) {
   Initialize();
 }
 
 BrowserCompositorOutputSurface::~BrowserCompositorOutputSurface() {
   DCHECK(CalledOnValidThread());
+  vsync_manager_->RemoveObserver(this);
   if (!HasClient())
     return;
   output_surface_map_->Remove(surface_id_);
 }
 
 void BrowserCompositorOutputSurface::Initialize() {
   CommandLine* command_line = CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kUIMaxFramesPending)) {
     std::string string_value = command_line->GetSwitchValueASCII(
         switches::kUIMaxFramesPending);
     int int_value;
     if (base::StringToInt(string_value, &int_value))
       capabilities_.max_frames_pending = int_value;
     else
       LOG(ERROR) << "Trouble parsing --" << switches::kUIMaxFramesPending;
   }
   capabilities_.adjust_deadline_for_parent = false;
+  vsync_manager_->AddObserver(this);
 
   DetachFromThread();
 }
 
 bool BrowserCompositorOutputSurface::BindToClient(
     cc::OutputSurfaceClient* client) {
   DCHECK(CalledOnValidThread());
 
   if (!OutputSurface::BindToClient(client))
     return false;
 
   output_surface_map_->AddWithID(this, surface_id_);
   if (reflector_)
     reflector_->OnSourceSurfaceReady(surface_id_);
   return true;
 }
 
 void BrowserCompositorOutputSurface::Reshape(const gfx::Size& size,
                                              float scale_factor) {
   OutputSurface::Reshape(size, scale_factor);
   if (reflector_.get())
     reflector_->OnReshape(size);
 }
 
 void BrowserCompositorOutputSurface::OnUpdateVSyncParameters(
     base::TimeTicks timebase,
     base::TimeDelta interval) {
   DCHECK(CalledOnValidThread());
   DCHECK(HasClient());
-  OnVSyncParametersChanged(timebase, interval);
-  compositor_message_loop_->PostTask(
-      FROM_HERE,
-      base::Bind(&ui::Compositor::OnUpdateVSyncParameters,
-                 compositor_, timebase, interval));
+  CommitVSyncParameters(timebase, interval);
+}
+
+void BrowserCompositorOutputSurface::OnUpdateVSyncParametersFromGpu(
+    base::TimeTicks timebase,
+    base::TimeDelta interval) {
+  DCHECK(CalledOnValidThread());
+  DCHECK(HasClient());
+  vsync_manager_->UpdateVSyncParameters(timebase, interval);
 }
 
 void BrowserCompositorOutputSurface::SetReflector(ReflectorImpl* reflector) {
   reflector_ = reflector;
 }
 
 }  // namespace content