Add medium image quality to software predecode.

cc/tiles/software_image_decode_controller_unittest.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 "cc/tiles/software_image_decode_controller.h"
 
 #include "cc/playback/draw_image.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
@@ skipping 384 matching lines @@
   EXPECT_TRUE(need_unref);
   EXPECT_TRUE(high_quality_task);
 
   DrawImage medium_quality_draw_image(
       image.get(), SkIRect::MakeWH(image->width(), image->height()),
       kMedium_SkFilterQuality,
       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
   scoped_refptr<ImageDecodeTask> medium_quality_task;
   need_unref = controller.GetTaskForImageAndRef(
       medium_quality_draw_image, prepare_tiles_id, &medium_quality_task);
-  // Medium quality isn't handled by the controller, so it won't ref it. Note
-  // that this will change when medium quality is handled and will need to be
-  // updated.
-  EXPECT_FALSE(need_unref);
+  EXPECT_TRUE(need_unref);
   EXPECT_TRUE(medium_quality_task);
   EXPECT_TRUE(high_quality_task.get() != medium_quality_task.get());
 
   DrawImage low_quality_draw_image(
       image.get(), SkIRect::MakeWH(image->width(), image->height()),
       kLow_SkFilterQuality,
       CreateMatrix(SkSize::Make(0.5f, 0.5f), is_decomposable));
   scoped_refptr<ImageDecodeTask> low_quality_task;
   need_unref = controller.GetTaskForImageAndRef(
       low_quality_draw_image, prepare_tiles_id, &low_quality_task);
   EXPECT_TRUE(need_unref);
   EXPECT_TRUE(low_quality_task);
   EXPECT_TRUE(high_quality_task.get() != low_quality_task.get());
   EXPECT_TRUE(medium_quality_task.get() != low_quality_task.get());
 
   controller.UnrefImage(high_quality_draw_image);
+  controller.UnrefImage(medium_quality_draw_image);
   controller.UnrefImage(low_quality_draw_image);
 }
 
 TEST(SoftwareImageDecodeControllerTest, GetTaskForImageSameImageDifferentSize) {
   SoftwareImageDecodeController controller;
   skia::RefPtr<SkImage> image = CreateImage(100, 100);
   bool is_decomposable = true;
   uint64_t prepare_tiles_id = 1;
   SkFilterQuality quality = kHigh_SkFilterQuality;
 
@@ skipping 598 matching lines @@
   // SkImage object.
   EXPECT_TRUE(decoded_draw_image.image() != image.get());
   EXPECT_EQ(kNone_SkFilterQuality, decoded_draw_image.filter_quality());
   EXPECT_TRUE(decoded_draw_image.is_scale_adjustment_identity());
 
   controller.DrawWithImageFinished(draw_image, decoded_draw_image);
   controller.UnrefImage(draw_image);
 }
 }  // namespace
 }  // namespace cc