Unifies LayerTreeHost::SetNeedsUpdateLayers and SetNeedsAnimate

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #if defined(OS_ANDROID)
@@ skipping 484 matching lines @@
     double duration_sec) {
   base::TimeDelta duration = base::TimeDelta::FromMicroseconds(
       duration_sec * base::Time::kMicrosecondsPerSecond);
   layer_tree_host_->StartPageScaleAnimation(
       gfx::Vector2d(destination.x, destination.y),
       use_anchor,
       new_page_scale,
       duration);
 }
 
-void RenderWidgetCompositor::setNeedsAnimate() {
-  layer_tree_host_->SetNeedsAnimate();
+void RenderWidgetCompositor::setNeedsUpdateLayers() {
+  layer_tree_host_->SetNeedsUpdateLayers();
 }
 
 void RenderWidgetCompositor::setNeedsRedraw() {
+  // TODO(trchen): This function is not doing what the name indicates?

[jamesr, 2013/11/19 00:54:26]

the purpose of this function is to request that whichever system is in control
of scheduling frames kick another one.  In single-threaded mode, that's the
RenderWidget so this calls RenderWidget::scheduleAnimation().  In threaded mode,
it's the scheduler inside cc so this calls cc::SetNeedsAnimate().  Both have the
practical effect of kicking the make-a-frame logic without causing any specific
damage.

It sounds like this is exactly the semantics you want with
SetNeedsUpdateLayers()

I don't think TODO is at all beneficial to have in the code

   if (threaded_)
-    layer_tree_host_->SetNeedsAnimate();
+    layer_tree_host_->SetNeedsUpdateLayers();
   else
     widget_->scheduleAnimation();
 }
 
-bool RenderWidgetCompositor::commitRequested() const {
-  return layer_tree_host_->CommitRequested();
-}
-
 void RenderWidgetCompositor::didStopFlinging() {
   layer_tree_host_->DidStopFlinging();
 }
 
 void RenderWidgetCompositor::registerForAnimations(blink::WebLayer* layer) {
   cc::Layer* cc_layer = static_cast<webkit::WebLayerImpl*>(layer)->layer();
   cc_layer->layer_animation_controller()->SetAnimationRegistrar(
       layer_tree_host_->animation_registrar());
 }
 
@@ skipping 133 matching lines @@
   widget_->OnSwapBuffersAborted();
 }
 
 void RenderWidgetCompositor::RateLimitSharedMainThreadContext() {
   cc::ContextProvider* provider =
       RenderThreadImpl::current()->SharedMainThreadContextProvider().get();
   provider->Context3d()->rateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content