Sky shouldn't crash on device rotate

sky/compositor/resource_manager.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_RESOURCE_MANAGER_H_
 #define SKY_COMPOSITOR_RESOURCE_MANAGER_H_
 
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "mojo/services/surfaces/public/interfaces/surfaces.mojom.h"
+#include "sky/compositor/texture_cache.h"
 
 namespace gfx {
 class Size;
 }
 
 namespace mojo {
 class GLContext;
 class GLTexture;
 }
 
 namespace sky {
 class Layer;
 class LayerHost;
 
 class ResourceManager {
  public:
   explicit ResourceManager(base::WeakPtr<mojo::GLContext> gl_context);
   ~ResourceManager();
 
   scoped_ptr<mojo::GLTexture> CreateTexture(const gfx::Size& size);
 
   mojo::TransferableResourcePtr CreateTransferableResource(Layer* layer);
   void ReturnResources(mojo::Array<mojo::ReturnedResourcePtr> resources);
 
  private:
   base::WeakPtr<mojo::GLContext> gl_context_;
   uint32_t next_resource_id_;
   base::hash_map<uint32_t, mojo::GLTexture*> resource_to_texture_map_;
-
-  ScopedVector<mojo::GLTexture> available_textures_;
+  TextureCache texture_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceManager);
 };
 
-}  // namespace examples
+}  // namespace sky
 
 #endif  // SKY_COMPOSITOR_RESOURCE_MANAGER_H_