Use WeakPtr for posting cc tasks to main thread

cc/layer_tree_host_unittest.cc

 // Copyright 2011 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 "cc/layer_tree_host.h"
 
 #include "base/synchronization/lock.h"
 #include "cc/content_layer.h"
 #include "cc/content_layer_client.h"
 #include "cc/layer_impl.h"
@@ skipping 779 matching lines @@
     }
 
     virtual void drawLayersOnThread(LayerTreeHostImpl* impl) OVERRIDE
     {
         impl->rootLayer()->setScrollable(true);
         impl->rootLayer()->setScrollOffset(gfx::Vector2d());
         impl->setPageScaleFactorAndLimits(impl->pageScaleFactor(), 0.5, 2);
 
         // We request animation only once.
         if (!m_animationRequested) {
-            m_mainThreadProxy->postTask(FROM_HERE, base::Bind(&LayerTreeHostTestStartPageScaleAnimation::requestStartPageScaleAnimation, base::Unretained(this)));
+            impl->proxy()->mainThread()->postTask(base::Bind(&LayerTreeHostTestStartPageScaleAnimation::requestStartPageScaleAnimation, base::Unretained(this)));
             m_animationRequested = true;
         }
     }
 
     virtual void applyScrollAndScale(gfx::Vector2d scrollDelta, float scale) OVERRIDE
     {
         gfx::Vector2d offset = m_layerTreeHost->rootLayer()->scrollOffset();
         m_layerTreeHost->rootLayer()->setScrollOffset(offset + scrollDelta);
         m_layerTreeHost->setPageScaleFactorAndLimits(scale, 0.5, 2);
     }
@@ skipping 2288 matching lines @@
     LayerTreeSettings settings;
     settings.maxPartialTextureUpdates = 4;
 
     scoped_ptr<LayerTreeHost> host = LayerTreeHost::create(&client, settings, scoped_ptr<Thread>());
     EXPECT_TRUE(host->initializeRendererIfNeeded());
     EXPECT_EQ(0u, host->settings().maxPartialTextureUpdates);
 }
 
 }  // namespace
 }  // namespace cc