cc: Add UMA for tracking decode duration for out of raster decodes.

cc/tiles/gpu_image_decode_cache_unittest.cc

 // Copyright 2016 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/tiles/gpu_image_decode_cache.h"
 
 #include "cc/paint/draw_image.h"
 #include "cc/test/test_context_provider.h"
 #include "cc/test/test_tile_task_runner.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 1445 matching lines @@
   TestGpuImageDecodeCache cache(context_provider.get());
 
   sk_sp<SkImage> image = CreateImage(1, 1);
   bool is_decomposable = true;
   SkMatrix matrix = CreateMatrix(SkSize::Make(1.0f, 1.0f), is_decomposable);
   DrawImage draw_image(CreatePaintImage(image),
                        SkIRect::MakeWH(image->width(), image->height()),
                        kLow_SkFilterQuality, matrix, DefaultColorSpace());
 
   scoped_refptr<TileTask> task;
-  bool need_unref =
-      cache.GetOutOfRasterDecodeTaskForImageAndRef(draw_image, &task);
+  bool need_unref = cache.GetOutOfRasterDecodeTaskForImageAndRef(
+      draw_image,
+      ImageDecodeCache::ImageDecodeType::OUT_OF_RASTER_CHECKER_IMAGING, &task);
   EXPECT_TRUE(need_unref);
   EXPECT_TRUE(task);
   EXPECT_TRUE(cache.IsInInUseCacheForTesting(draw_image));
 
   // Run the decode task.
   TestTileTaskRunner::ProcessTask(task.get());
 
   // The image should remain in the cache till we unref it.
   EXPECT_TRUE(cache.IsInInUseCacheForTesting(draw_image));
   cache.UnrefImage(draw_image);
@@ skipping 231 matching lines @@
   TestTileTaskRunner::ProcessTask(second_task->dependencies()[0].get());
   TestTileTaskRunner::ProcessTask(second_task.get());
 
   cache.UnrefImage(first_draw_image);
   cache.UnrefImage(second_draw_image);
   cache.UnrefImage(third_draw_image);
 }
 
 }  // namespace
 }  // namespace cc