Allow task pools to reason about transparency.

cc/tiles/tile_manager_perftest.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/location.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "cc/debug/lap_timer.h"
 #include "cc/raster/raster_buffer.h"
 #include "cc/test/begin_frame_args_test.h"
@@ skipping 44 matching lines @@
          it != completed_tasks_.end();
          ++it) {
       RasterTask* task = it->get();
 
       task->WillComplete();
       task->CompleteOnOriginThread(this);
       task->DidComplete();
     }
     completed_tasks_.clear();
   }
-  ResourceFormat GetResourceFormat() const override { return RGBA_8888; }
-  bool GetResourceRequiresSwizzle() const override {
-    return !PlatformColor::SameComponentOrder(GetResourceFormat());
+  ResourceFormat GetResourceFormat(bool must_support_alpha) const override {
+    return RGBA_8888;
+  }
+  bool GetResourceRequiresSwizzle(bool must_support_alpha) const override {
+    return !PlatformColor::SameComponentOrder(
+        GetResourceFormat(must_support_alpha));
   }
 
   // Overridden from TileTaskClient:
   scoped_ptr<RasterBuffer> AcquireBufferForRaster(
       const Resource* resource,
       uint64_t new_content_id,
       uint64_t previous_content_id) override {
     return nullptr;
   }
   void ReleaseBufferForRaster(scoped_ptr<RasterBuffer> buffer) override {}
@@ skipping 394 matching lines @@
   RunEvictionQueueConstructAndIterateTest("10_64", 10, 64);
   RunEvictionQueueConstructAndIterateTest("10_128", 10, 128);
   RunEvictionQueueConstructAndIterateTest("50_16", 50, 16);
   RunEvictionQueueConstructAndIterateTest("50_32", 50, 32);
   RunEvictionQueueConstructAndIterateTest("50_64", 50, 64);
   RunEvictionQueueConstructAndIterateTest("50_128", 50, 128);
 }
 
 }  // namespace
 }  // namespace cc