cc: Fix recording of GPU rasterization histogram for renderer compositor.

cc/layers/scrollbar_layer_unittest.cc

 // Copyright 2012 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 "base/containers/hash_tables.h"
 #include "base/thread_task_runner_handle.h"
 #include "cc/animation/scrollbar_animation_controller.h"
 #include "cc/layers/append_quads_data.h"
 #include "cc/layers/painted_scrollbar_layer.h"
 #include "cc/layers/painted_scrollbar_layer_impl.h"
@@ skipping 45 matching lines @@
   layer_tree_root->AddChild(child1);
   layer_tree_root->InsertChild(child2, reverse_order ? 0 : 1);
   host->SetRootLayer(layer_tree_root);
   return host->CommitAndCreateLayerImplTree();
 }
 
 class FakeResourceTrackingLayerTreeHost : public FakeLayerTreeHost {
  public:
   FakeResourceTrackingLayerTreeHost(FakeLayerTreeHostClient* client,
                                     LayerTreeHost::InitParams* params)
-      : FakeLayerTreeHost(client, params),
+      : FakeLayerTreeHost(client, params, CompositorMode::SingleThreaded),
         next_id_(1),
         total_ui_resource_created_(0),
         total_ui_resource_deleted_(0) {
     InitializeSingleThreaded(client, base::ThreadTaskRunnerHandle::Get(),
                              nullptr);
   }
 
   UIResourceId CreateUIResource(UIResourceClient* content) override {
     total_ui_resource_created_++;
     UIResourceId nid = next_id_++;
@@ skipping 922 matching lines @@
   TestScale(gfx::Rect(1240, 0, 15, 1333), 2.7754839f);
   TestScale(gfx::Rect(1240, 0, 15, 677), 2.46677136f);
 
   // Horizontal Scrollbars.
   TestScale(gfx::Rect(0, 1240, 1333, 15), 2.7754839f);
   TestScale(gfx::Rect(0, 1240, 677, 15), 2.46677136f);
 }
 
 }  // namespace
 }  // namespace cc