Update GatherPixelRefDevice to the new SkImage/SkPixelRef API

cc/playback/display_list_raster_source_unittest.cc

 // Copyright 2013 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 "base/memory/scoped_ptr.h"
 #include "cc/playback/display_list_raster_source.h"
 #include "cc/test/fake_display_list_recording_source.h"
 #include "cc/test/skia_common.h"
 #include "skia/ext/refptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 158 matching lines @@
   EXPECT_EQ(analysis.solid_color, SkColorSetARGB(0, 0, 0, 0));
 }
 
 TEST(DisplayListRasterSourceTest, PixelRefIteratorDiscardableRefsOneTile) {
   gfx::Size layer_bounds(512, 512);
 
   scoped_ptr<FakeDisplayListRecordingSource> recording_source =
       FakeDisplayListRecordingSource::CreateFilledRecordingSource(layer_bounds);
 
   SkBitmap discardable_bitmap[2][2];
-  CreateBitmap(gfx::Size(32, 32), "discardable", &discardable_bitmap[0][0]);
-  CreateBitmap(gfx::Size(32, 32), "discardable", &discardable_bitmap[0][1]);
-  CreateBitmap(gfx::Size(32, 32), "discardable", &discardable_bitmap[1][1]);
+  CreateDiscardableBitmap(gfx::Size(32, 32), &discardable_bitmap[0][0]);
+  CreateDiscardableBitmap(gfx::Size(32, 32), &discardable_bitmap[0][1]);
+  CreateDiscardableBitmap(gfx::Size(32, 32), &discardable_bitmap[1][1]);
 
   // Discardable pixel refs are found in the following cells:
   // |---|---|
   // | x | x |
   // |---|---|
   // |   | x |
   // |---|---|
   recording_source->add_draw_bitmap(discardable_bitmap[0][0], gfx::Point(0, 0));
   recording_source->add_draw_bitmap(discardable_bitmap[0][1],
                                     gfx::Point(260, 0));
@@ skipping 402 matching lines @@
   scoped_refptr<DisplayListRasterSource> raster =
       DisplayListRasterSource::CreateFromDisplayListRecordingSource(
           recording_source.get(), false);
   size_t total_memory_usage = raster->GetPictureMemoryUsage();
   EXPECT_GE(total_memory_usage, kReportedMemoryUsageInBytes);
   EXPECT_LT(total_memory_usage, 2 * kReportedMemoryUsageInBytes);
 }
 
 }  // namespace
 }  // namespace cc