Add compile flag for enabling the compostior

sky/viewer/document_view.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 "sky/viewer/document_view.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 139 matching lines @@
   shell_->ConnectToApplication("mojo:native_viewport_service",
                                mojo::GetProxy(&gpu_service_provider));
   mojo::InterfacePtr<mojo::Gpu> gpu_service;
   mojo::ConnectToService(gpu_service_provider.get(), &gpu_service);
   web_layer_tree_view_impl_.reset(new WebLayerTreeViewImpl(
       compositor_thread_, surfaces_service.Pass(), gpu_service.Pass()));
 
   return web_layer_tree_view_impl_.get();
 }
 
+void DocumentView::scheduleAnimation() {
+  DCHECK(web_view_);
+
+  if (!web_view_->settings()->compositorIsEnabled())
+    web_layer_tree_view_impl_->setNeedsAnimate();
+}
+
 mojo::View* DocumentView::createChildFrame(const blink::WebURL& url) {
   if (!root_)
     return nullptr;
 
   mojo::View* child = mojo::View::Create(root_->view_manager());
   root_->AddChild(child);
   child->Embed(mojo::String::From(url.string().utf8()));
 
   return child;
 }
@@ skipping 70 matching lines @@
 
 void DocumentView::OnViewInputEvent(
     mojo::View* view, const mojo::EventPtr& event) {
   scoped_ptr<blink::WebInputEvent> web_event =
       event.To<scoped_ptr<blink::WebInputEvent> >();
   if (web_event)
     web_view_->handleInputEvent(*web_event);
 }
 
 }  // namespace sky