[compositorworker] compositor proxy mutation updates underlying layers

third_party/WebKit/Source/platform/graphics/CompositorMutableStateProvider.h

 // Copyright 2016 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 CompositorMutableStateProvider_h
 #define CompositorMutableStateProvider_h
 
 #include "platform/PlatformExport.h"
-#include "wtf/PassOwnPtr.h"
 
 #include <cstdint>
+#include <memory>
 
 namespace cc {
 class LayerTreeImpl;
 } // namespace cc
 
 namespace blink {
 
 class CompositorMutableState;
 struct CompositorMutations;
 
 // This class is a window onto compositor-owned state. It vends out wrappers
 // around per-element bits of this state.
 class PLATFORM_EXPORT CompositorMutableStateProvider {
 public:
     CompositorMutableStateProvider(cc::LayerTreeImpl*, CompositorMutations*);
     ~CompositorMutableStateProvider();
 
-    PassOwnPtr<CompositorMutableState> getMutableStateFor(uint64_t elementId);
+    std::unique_ptr<CompositorMutableState> getMutableStateFor(uint64_t elementId);
+
 private:
-    cc::LayerTreeImpl* m_state;
+    cc::LayerTreeImpl* m_tree;
     CompositorMutations* m_mutations;
 };
 
 } // namespace blink
 
 #endif // CompositorMutableStateProvider_h