cc : Make CallFunctionForSubtree on impl use layer iterator

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 6458 matching lines @@
     affected_by_page_scale_.push_back(page_scale_grandchild->id());
 
     not_affected_by_page_scale_.push_back(root->id());
     not_affected_by_page_scale_.push_back(pre_page_scale->id());
     not_affected_by_page_scale_.push_back(post_page_scale->id());
   }
 
   void BeginTest() override { PostSetNeedsCommitToMainThread(); }
 
   void CommitCompleteOnThread(LayerTreeHostImpl* host_impl) override {
-    LayerTreeHostCommon::CallFunctionForSubtree(
-        host_impl->sync_tree()->root_layer(), [this](LayerImpl* layer) {
+    LayerTreeHostCommon::CallFunctionForEveryLayer(
+        host_impl->sync_tree(), [this](LayerImpl* layer) {
           const std::vector<int>& list =
               layer->IsAffectedByPageScale()
                   ? this->affected_by_page_scale_
                   : this->not_affected_by_page_scale_;
           EXPECT_TRUE(std::find(list.begin(), list.end(), layer->id()) !=
                       list.end());
         });
 
     EndTest();
   }
@@ skipping 105 matching lines @@
     EndTest();
   }
 
   void AfterTest() override {}
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestPaintedDeviceScaleFactor);
 
 }  // namespace
 }  // namespace cc