Allow task pools to reason about transparency.

cc/raster/gpu_tile_task_worker_pool.cc

 // Copyright 2014 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/raster/gpu_tile_task_worker_pool.h"
 
 #include <algorithm>
 
 #include "base/trace_event/trace_event.h"
 #include "cc/playback/raster_source.h"
@@ skipping 183 matching lines @@
 
 void GpuTileTaskWorkerPool::CheckForCompletedTasks() {
   TRACE_EVENT0("cc", "GpuTileTaskWorkerPool::CheckForCompletedTasks");
 
   task_graph_runner_->CollectCompletedTasks(namespace_token_,
                                             &completed_tasks_);
   CompleteTasks(completed_tasks_);
   completed_tasks_.clear();
 }
 
-ResourceFormat GpuTileTaskWorkerPool::GetResourceFormat() const {
+ResourceFormat GpuTileTaskWorkerPool::GetResourceFormat(
+    bool must_support_alpha) const {
   return rasterizer_->resource_provider()->best_render_buffer_format();
 }
 
-bool GpuTileTaskWorkerPool::GetResourceRequiresSwizzle() const {
+bool GpuTileTaskWorkerPool::GetResourceRequiresSwizzle(
+    bool must_support_alpha) const {
   // This doesn't require a swizzle because we rasterize to the correct format.
   return false;
 }
 
 void GpuTileTaskWorkerPool::CompleteTasks(const Task::Vector& tasks) {
   for (auto& task : tasks) {
     TileTask* tile_task = static_cast<TileTask*>(task.get());
 
     tile_task->WillComplete();
     tile_task->CompleteOnOriginThread(this);
@@ skipping 18 matching lines @@
 void GpuTileTaskWorkerPool::OnTaskSetFinished(TaskSet task_set) {
   TRACE_EVENT1("cc", "GpuTileTaskWorkerPool::OnTaskSetFinished", "task_set",
                task_set);
 
   DCHECK(tasks_pending_[task_set]);
   tasks_pending_[task_set] = false;
   client_->DidFinishRunningTileTasks(task_set);
 }
 
 }  // namespace cc