Move visual rect unioning between paired items to cc::DisplayItemList.

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 114 matching lines @@
     gfx::Rect yellow_rect = blue_top_ ? bottom : top;
 
     SkPaint paint;
     paint.setStyle(SkPaint::kFill_Style);
 
     paint.setColor(SK_ColorBLUE);
     canvas->drawRect(gfx::RectToSkRect(blue_rect), paint);
     paint.setColor(SK_ColorYELLOW);
     canvas->drawRect(gfx::RectToSkRect(yellow_rect), paint);
 
-    display_list->CreateAndAppendItem<DrawingDisplayItem>(
+    display_list->CreateAndAppendDrawingItem<DrawingDisplayItem>(
         PaintableRegion(), recorder.finishRecordingAsPicture());
     display_list->Finalize();
     return display_list;
   }
 
   bool FillsBoundsCompletely() const override { return true; }
   size_t GetApproximateUnsharedMemoryUsage() const override { return 0; }
 
   void set_blue_top(bool b) { blue_top_ = b; }
 
@@ skipping 88 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)