aura: Allow in process ContextProvider to hold onscreen contexts.

ui/compositor/compositor.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 "ui/compositor/compositor.h"
 
 #include <algorithm>
 #include <deque>
 
 #include "base/bind.h"
@@ skipping 119 matching lines @@
 
 void DefaultContextFactory::RemoveReflector(
     scoped_refptr<Reflector> reflector) {
 }
 
 scoped_refptr<cc::ContextProvider>
 DefaultContextFactory::OffscreenContextProviderForMainThread() {
   if (!offscreen_contexts_main_thread_.get() ||
       !offscreen_contexts_main_thread_->DestroyedOnMainThread()) {
     offscreen_contexts_main_thread_ =
-        webkit::gpu::ContextProviderInProcess::Create();
+        webkit::gpu::ContextProviderInProcess::CreateOffscreen();
     if (offscreen_contexts_main_thread_.get() &&
         !offscreen_contexts_main_thread_->BindToCurrentThread())
       offscreen_contexts_main_thread_ = NULL;
   }
   return offscreen_contexts_main_thread_;
 }
 
 scoped_refptr<cc::ContextProvider>
 DefaultContextFactory::OffscreenContextProviderForCompositorThread() {
   if (!offscreen_contexts_compositor_thread_.get() ||
       !offscreen_contexts_compositor_thread_->DestroyedOnMainThread()) {
     offscreen_contexts_compositor_thread_ =
-        webkit::gpu::ContextProviderInProcess::Create();
+        webkit::gpu::ContextProviderInProcess::CreateOffscreen();
   }
   return offscreen_contexts_compositor_thread_;
 }
 
 void DefaultContextFactory::RemoveCompositor(Compositor* compositor) {
 }
 
 bool DefaultContextFactory::DoesCreateTestContexts() { return false; }
 
 TestContextFactory::TestContextFactory() {}
@@ skipping 595 matching lines @@
 }
 
 void Compositor::NotifyEnd() {
   last_ended_frame_++;
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingEnded(this));
 }
 
 }  // namespace ui