Change cc::ElementId to be a uint64_t

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

Index: third_party/WebKit/Source/platform/graphics/CompositorElementId.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/CompositorElementId.cpp b/third_party/WebKit/Source/platform/graphics/CompositorElementId.cpp
index eeb495fbacd4780e0671a07ae53022b945c3aa39..ec69b6e0d91ca812e651e1560bb58dfc3e813a84 100644
--- a/third_party/WebKit/Source/platform/graphics/CompositorElementId.cpp
+++ b/third_party/WebKit/Source/platform/graphics/CompositorElementId.cpp
@@ -7,9 +7,26 @@
 namespace blink {
 
 CompositorElementId CreateCompositorElementId(
-    int dom_node_id,
+    DOMNodeId dom_node_id,
     CompositorSubElementId sub_element_id) {
-  return CompositorElementId(dom_node_id, static_cast<int>(sub_element_id));
+  DCHECK(dom_node_id > 0 &&
+         dom_node_id <
+             std::numeric_limits<DOMNodeId>::max() / kNumSubElementTypes);
+  CompositorElementId element_id;
+  element_id.id = dom_node_id
+                  << 2;  // Shift to make room for sub_element_id enum bits.
+  element_id.id += static_cast<uint64_t>(sub_element_id);
+  return element_id;
+}
+
+DOMNodeId DomNodeIdFromCompositorElementId(CompositorElementId element_id) {
+  return element_id.id >> 2;
+}
+
+CompositorSubElementId SubElementIdFromCompositorElementId(
+    CompositorElementId element_id) {
+  return static_cast<CompositorSubElementId>(element_id.id %
+                                             kNumSubElementTypes);
 }
 
 }  // namespace blink