Avoid exposing cc::Layer tree to CompositorProxy

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

 // 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.
 
 #include "platform/graphics/CompositorMutableStateProvider.h"
 
-#include "cc/layers/layer_impl.h"
-#include "cc/trees/layer_tree_impl.h"
 #include "platform/graphics/CompositorElementId.h"
-#include "platform/graphics/CompositorMutableProperties.h"
 #include "platform/graphics/CompositorMutableState.h"
 #include "platform/graphics/CompositorMutation.h"
 #include "wtf/PtrUtil.h"
 #include <memory>
 
 namespace blink {
 
 CompositorMutableStateProvider::CompositorMutableStateProvider(
-    cc::LayerTreeImpl* treeImpl,
+    ProxyCompositorMutablePropertiesMap* inputProperties,
     CompositorMutations* mutations)
-    : m_tree(treeImpl), m_mutations(mutations) {}
+    : m_inputProperties(inputProperties), m_mutations(mutations) {}
 
 CompositorMutableStateProvider::~CompositorMutableStateProvider() {}
 
 std::unique_ptr<CompositorMutableState>
-CompositorMutableStateProvider::getMutableStateFor(uint64_t elementId) {
-  cc::LayerImpl* mainLayer = m_tree->LayerByElementId(
-      createCompositorElementId(elementId, CompositorSubElementId::Primary));
-  cc::LayerImpl* scrollLayer = m_tree->LayerByElementId(
-      createCompositorElementId(elementId, CompositorSubElementId::Scroll));
+CompositorMutableStateProvider::getMutableStateFor(uint64_t proxyId) {
+  const auto it = m_inputProperties->find(proxyId);
+  if (it == m_inputProperties->end())
+    return nullptr;
 
-  if (!mainLayer && !scrollLayer)
-    return nullptr;
+  CompositorMutableProperties* properties = &it->second;
 
   // Ensure that we have an entry in the map for |elementId| but do as few
   // allocations and queries as possible. This will update the map only if we
   // have not added a value for |elementId|.
-  auto result = m_mutations->map.insert(elementId, nullptr);
+  auto result = m_mutations->map.insert(properties->elementId, nullptr);
 
   // Only if this is a new entry do we want to allocate a new mutation.
   if (result.isNewEntry)
     result.storedValue->value = WTF::wrapUnique(new CompositorMutation);
 
-  return WTF::wrapUnique(new CompositorMutableState(
-      result.storedValue->value.get(), mainLayer, scrollLayer));
+  return WTF::wrapUnique(
+      new CompositorMutableState(result.storedValue->value.get(), properties));
 }
 
 }  // namespace blink