Allow task pools to reason about transparency.

cc/raster/zero_copy_tile_task_worker_pool.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 "cc/raster/zero_copy_tile_task_worker_pool.h"
 
 #include <algorithm>
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 47 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(RasterBufferImpl);
 };
 
 }  // namespace
 
 // static
 scoped_ptr<TileTaskWorkerPool> ZeroCopyTileTaskWorkerPool::Create(
     base::SequencedTaskRunner* task_runner,
     TaskGraphRunner* task_graph_runner,
-    ResourceProvider* resource_provider) {
+    ResourceProvider* resource_provider,
+    bool use_rgba_4444_texture_format) {
   return make_scoped_ptr<TileTaskWorkerPool>(new ZeroCopyTileTaskWorkerPool(
-      task_runner, task_graph_runner, resource_provider));
+      task_runner, task_graph_runner, resource_provider,
+      use_rgba_4444_texture_format));
 }
 
 ZeroCopyTileTaskWorkerPool::ZeroCopyTileTaskWorkerPool(
     base::SequencedTaskRunner* task_runner,
     TaskGraphRunner* task_graph_runner,
-    ResourceProvider* resource_provider)
+    ResourceProvider* resource_provider,
+    bool use_rgba_4444_texture_format)
     : task_runner_(task_runner),
       task_graph_runner_(task_graph_runner),
       namespace_token_(task_graph_runner->GetNamespaceToken()),
       resource_provider_(resource_provider),
-      task_set_finished_weak_ptr_factory_(this) {
-}
+      use_rgba_4444_texture_format_(use_rgba_4444_texture_format),
+      task_set_finished_weak_ptr_factory_(this) {}
 
 ZeroCopyTileTaskWorkerPool::~ZeroCopyTileTaskWorkerPool() {
 }
 
 TileTaskRunner* ZeroCopyTileTaskWorkerPool::AsTileTaskRunner() {
   return this;
 }
 
 void ZeroCopyTileTaskWorkerPool::SetClient(TileTaskRunnerClient* client) {
   client_ = client;
@@ skipping 79 matching lines @@
        it != completed_tasks_.end(); ++it) {
     TileTask* task = static_cast<TileTask*>(it->get());
 
     task->WillComplete();
     task->CompleteOnOriginThread(this);
     task->DidComplete();
   }
   completed_tasks_.clear();
 }
 
-ResourceFormat ZeroCopyTileTaskWorkerPool::GetResourceFormat() const {
-  return resource_provider_->memory_efficient_texture_format();
+ResourceFormat ZeroCopyTileTaskWorkerPool::GetResourceFormat(
+    bool must_support_alpha) const {
+  return use_rgba_4444_texture_format_
+             ? RGBA_4444
+             : resource_provider_->best_texture_format();
 }
 
-bool ZeroCopyTileTaskWorkerPool::GetResourceRequiresSwizzle() const {
-  return !PlatformColor::SameComponentOrder(GetResourceFormat());
+bool ZeroCopyTileTaskWorkerPool::GetResourceRequiresSwizzle(
+    bool must_support_alpha) const {
+  return !PlatformColor::SameComponentOrder(
+      GetResourceFormat(must_support_alpha));
 }
 
 scoped_ptr<RasterBuffer> ZeroCopyTileTaskWorkerPool::AcquireBufferForRaster(
     const Resource* resource,
     uint64_t resource_content_id,
     uint64_t previous_content_id) {
   return make_scoped_ptr<RasterBuffer>(
       new RasterBufferImpl(resource_provider_, resource));
 }
 
@@ skipping 23 matching lines @@
       new base::trace_event::TracedValue();
 
   state->BeginArray("tasks_pending");
   for (TaskSet task_set = 0; task_set < kNumberOfTaskSets; ++task_set)
     state->AppendBoolean(tasks_pending_[task_set]);
   state->EndArray();
   return state;
 }
 
 }  // namespace cc