Fix several leaks in the Sky compositor

sky/compositor/layer_host.h

 // 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.
 
 #ifndef SKY_COMPOSITOR_LAYER_HOST_H_
 #define SKY_COMPOSITOR_LAYER_HOST_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "mojo/gpu/gl_context_owner.h"
 #include "mojo/skia/ganesh_context.h"
 #include "sky/compositor/layer_host_client.h"
 #include "sky/compositor/resource_manager.h"
 #include "sky/compositor/surface_holder.h"
 
 namespace sky {
 class ResourceManager;
 class Layer;
 class LayerHostClient;
 
 class LayerHost : public SurfaceHolder::Client {
  public:
   explicit LayerHost(LayerHostClient* client);
   ~LayerHost();
 
   LayerHostClient* client() const { return client_; }
 
   const base::WeakPtr<mojo::GLContext>& gl_context() const {
-    return gl_context_;
+    return gl_context_owner_.context();
   }
 
   mojo::GaneshContext* ganesh_context() const {
     return const_cast<mojo::GaneshContext*>(&ganesh_context_);
   }
 
   ResourceManager* resource_manager() const {
     return const_cast<ResourceManager*>(&resource_manager_);
   }
 
@@ skipping 16 matching lines @@
   void BeginFrameSoon();
   void BeginFrame();
 
   void Upload(Layer* layer);
   void DidCompleteFrame();
 
   LayerHostClient* client_;
   State state_;
   bool frame_requested_;
   SurfaceHolder surface_holder_;
-  base::WeakPtr<mojo::GLContext> gl_context_;
+  mojo::GLContextOwner gl_context_owner_;
   mojo::GaneshContext ganesh_context_;
   ResourceManager resource_manager_;
   scoped_refptr<Layer> root_layer_;
 
   base::WeakPtrFactory<LayerHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerHost);
 };
 
 }  // namespace sky
 
 #endif  // SKY_COMPOSITOR_LAYER_HOST_H_