Use element id's for animations

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

Index: third_party/WebKit/Source/platform/graphics/CompositorMutableStateProvider.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/CompositorMutableStateProvider.cpp b/third_party/WebKit/Source/platform/graphics/CompositorMutableStateProvider.cpp
index cb2d9b1158971a96cff76f152a1fb4f90688a073..a80acbf6fe5a1a0b2cee8724044d5bfe2e7320f6 100644
--- a/third_party/WebKit/Source/platform/graphics/CompositorMutableStateProvider.cpp
+++ b/third_party/WebKit/Source/platform/graphics/CompositorMutableStateProvider.cpp
@@ -6,6 +6,8 @@
 
 #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/PassOwnPtr.h"
@@ -23,9 +25,10 @@ CompositorMutableStateProvider::~CompositorMutableStateProvider() {}
 PassOwnPtr<CompositorMutableState>
 CompositorMutableStateProvider::getMutableStateFor(uint64_t element_id)
 {
-    cc::LayerTreeImpl::ElementLayers layers = m_state->GetMutableLayers(element_id);
+    cc::LayerImpl* mainLayer = m_state->LayerByElementId(cc::ElementId(element_id));
+    cc::LayerImpl* scrollLayer = m_state->LayerByElementId(createCompositorElementId(element_id, CompositorSubElementId::Value::Scroll));
 
-    if (!layers.main && !layers.scroll)
+    if (!mainLayer && !scrollLayer)
         return nullptr;
 
     // Ensure that we have an entry in the map for |element_id| but do as few
@@ -37,7 +40,7 @@ CompositorMutableStateProvider::getMutableStateFor(uint64_t element_id)
     if (result.isNewEntry)
         result.storedValue->value = adoptPtr(new CompositorMutation);
 
-    return adoptPtr(new CompositorMutableState(result.storedValue->value.get(), layers.main, layers.scroll));
+    return adoptPtr(new CompositorMutableState(result.storedValue->value.get(), mainLayer, scrollLayer));
 }
 
 } // namespace blink