Switch cc to std::unordered_*.

cc/blink/web_compositor_mutable_state_provider_impl.h

 // Copyright 2015 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 CC_BLINK_WEB_COMPOSITOR_MUTABLE_STATE_PROVIDER_IMPL_H_
 #define CC_BLINK_WEB_COMPOSITOR_MUTABLE_STATE_PROVIDER_IMPL_H_
 
 #include "base/compiler_specific.h"
-#include "base/containers/hash_tables.h"
 #include "cc/animation/layer_tree_mutation.h"
 #include "cc/blink/cc_blink_export.h"
 
 #include "third_party/WebKit/public/platform/WebCompositorMutableStateProvider.h"
 
 namespace cc {
 class LayerTreeImpl;
 }  // namespace cc
 
 namespace cc_blink {
@@ skipping 15 matching lines @@
   getMutableStateFor(uint64_t element_id) override WARN_UNUSED_RESULT;
 
  private:
   cc::LayerTreeImpl* state_;
   cc::LayerTreeMutationMap* mutations_;
 };
 
 }  // namespace cc_blink
 
 #endif  // CC_BLINK_WEB_COMPOSITOR_MUTABLE_STATE_PROVIDER_IMPL_H_