Change cc::ElementId to be a uint64_t

cc/trees/layer_tree_host_unittest.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1360 matching lines @@
 class LayerTreeHostTestTransformTreeDamageIsUpdated : public LayerTreeHostTest {
  protected:
   void SetupTree() override {
     root_ = Layer::Create();
     child_ = Layer::Create();
     grand_child_ = Layer::Create();
 
     root_->SetBounds(gfx::Size(50, 50));
 
     // Make sure child is registerd for animation.
-    child_->SetElementId(ElementId(2, 0));
+    child_->SetElementId(ElementId(2));
 
     // Make sure child and grand_child have transform nodes.
     gfx::Transform rotation;
     rotation.RotateAboutZAxis(45.0);
     child_->SetTransform(rotation);
     grand_child_->SetTransform(rotation);
 
     root_->AddChild(child_);
     child_->AddChild(grand_child_);
     layer_tree_host()->SetRootLayer(root_);
@@ skipping 6344 matching lines @@
   void AfterTest() override {}
 
  private:
   bool received_ack_ = false;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestDiscardAckAfterRelease);
 
 }  // namespace
 }  // namespace cc