Use element id's for animations

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

Index: third_party/WebKit/Source/platform/graphics/CompositorElementId.h
diff --git a/third_party/WebKit/Source/platform/graphics/CompositorElementId.h b/third_party/WebKit/Source/platform/graphics/CompositorElementId.h
new file mode 100644
index 0000000000000000000000000000000000000000..cd9438913a74d31349a64a91f990e5f3cb11743a
--- /dev/null
+++ b/third_party/WebKit/Source/platform/graphics/CompositorElementId.h
@@ -0,0 +1,20 @@
+// 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 CompositorElementId_h
+#define CompositorElementId_h
+
+#include "cc/animation/element_id.h"
+
+namespace blink {
+
+static const int kScrollSubElement = 1;
+static const int kViewportScrollSubElement = 2;
+static const int kLinkHighlightSubElement = 3;

[ajuma, 2016/06/01 23:53:42]

I think these should go into a sub-namespace (e.g. CompositorElementSubId).

[Ian Vollick, 2016/06/02 19:03:11]

Done.

+
+using CompositorElementId = cc::ElementId;
+
+} // namespace blink
+
+#endif // CompositorElementId_h