Avoid exposing cc::Layer tree to CompositorProxy

third_party/WebKit/Source/platform/graphics/CompositorMutation.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 CompositorMutation_h
 #define CompositorMutation_h
 
 #include <memory>
 #include "platform/graphics/CompositorMutableProperties.h"
 #include "platform/wtf/HashMap.h"
@@ skipping 31 matching lines @@
   }
   bool IsTransformMutated() const {
     return mutated_flags_ & CompositorMutableProperty::kTransform;
   }
 
   float Opacity() const { return opacity_; }
   float ScrollLeft() const { return scroll_left_; }
   float ScrollTop() const { return scroll_top_; }
   SkMatrix44 Transform() const { return transform_; }
 
+  uint32_t mutatedProperties() const { return mutated_flags_; }
+
  private:
   uint32_t mutated_flags_ = 0;
   float opacity_ = 0;
   float scroll_left_ = 0;
   float scroll_top_ = 0;
   SkMatrix44 transform_;
 };
 
 struct CompositorMutations {
   HashMap<uint64_t, std::unique_ptr<CompositorMutation>> map;
 };
 
 }  // namespace blink
 
 #endif  // CompositorMutation_h