cc: Merge LayerTree into the LayerTreeHost.

cc/trees/layer_tree_host_pixeltest_tiles.cc

 // Copyright 2015 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 <stddef.h>
 
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/picture_layer.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/playback/display_item_list.h"
@@ skipping 51 matching lines @@
     }
   }
 
   void BeginTest() override {
     // Don't set up a readback target at the start of the test.
     PostSetNeedsCommitToMainThread();
   }
 
   void DoReadback() {
     Layer* target =
-        readback_target_ ? readback_target_ : layer_tree()->root_layer();
+        readback_target_ ? readback_target_ : layer_tree_host()->root_layer();
     target->RequestCopyOfOutput(CreateCopyOutputRequest());
   }
 
   void RunRasterPixelTest(bool threaded,
                           RasterMode mode,
                           scoped_refptr<Layer> content_root,
                           base::FilePath file_name) {
     raster_mode_ = mode;
 
     PixelTestType test_type = PIXEL_TEST_SOFTWARE;
@@ skipping 164 matching lines @@
        FullRaster_SingleThread_GpuRaster) {
   RunRasterPixelTest(
       false, FULL_GPU, picture_layer_,
       base::FilePath(FILE_PATH_LITERAL("blue_yellow_flipped.png")));
 }
 
 }  // namespace
 }  // namespace cc
 
 #endif  // !defined(OS_ANDROID)