Reland Allow one-copy and zero-copy task tile worker pools to use compressed textures.

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 <stdint.h>
 
 #include <algorithm>
 
@@ skipping 50 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,
-    bool use_rgba_4444_texture_format) {
-  return make_scoped_ptr<TileTaskWorkerPool>(new ZeroCopyTileTaskWorkerPool(
-      task_runner, task_graph_runner, resource_provider,
-      use_rgba_4444_texture_format));
+    ResourceFormat preferred_tile_format) {
+  return make_scoped_ptr<TileTaskWorkerPool>(
+      new ZeroCopyTileTaskWorkerPool(task_runner, task_graph_runner,
+                                     resource_provider, preferred_tile_format));
 }
 
 ZeroCopyTileTaskWorkerPool::ZeroCopyTileTaskWorkerPool(
     base::SequencedTaskRunner* task_runner,
     TaskGraphRunner* task_graph_runner,
     ResourceProvider* resource_provider,
-    bool use_rgba_4444_texture_format)
+    ResourceFormat preferred_tile_format)
     : task_runner_(task_runner),
       task_graph_runner_(task_graph_runner),
       namespace_token_(task_graph_runner->GetNamespaceToken()),
       resource_provider_(resource_provider),
-      use_rgba_4444_texture_format_(use_rgba_4444_texture_format) {}
+      preferred_tile_format_(preferred_tile_format) {}
 
 ZeroCopyTileTaskWorkerPool::~ZeroCopyTileTaskWorkerPool() {
 }
 
 TileTaskRunner* ZeroCopyTileTaskWorkerPool::AsTileTaskRunner() {
   return this;
 }
 
 void ZeroCopyTileTaskWorkerPool::Shutdown() {
   TRACE_EVENT0("cc", "ZeroCopyTileTaskWorkerPool::Shutdown");
@@ skipping 21 matching lines @@
 
     task->WillComplete();
     task->CompleteOnOriginThread(this);
     task->DidComplete();
   }
   completed_tasks_.clear();
 }
 
 ResourceFormat ZeroCopyTileTaskWorkerPool::GetResourceFormat(
     bool must_support_alpha) const {
-  return use_rgba_4444_texture_format_
-             ? RGBA_4444
-             : resource_provider_->best_texture_format();
+  if (resource_provider_->IsResourceFormatSupported(preferred_tile_format_) &&
+      (DoesResourceFormatSupportAlpha(preferred_tile_format_) ||
+       !must_support_alpha)) {
+    return preferred_tile_format_;
+  }
+
+  return resource_provider_->best_texture_format();
 }
 
 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));
 }
 
 void ZeroCopyTileTaskWorkerPool::ReleaseBufferForRaster(
     scoped_ptr<RasterBuffer> buffer) {
   // Nothing to do here. RasterBufferImpl destructor cleans up after itself.
 }
 
 }  // namespace cc