Allow one-copy task tile worker pool to use compressed textures.

cc/raster/zero_copy_tile_task_worker_pool.cc

Index: cc/raster/zero_copy_tile_task_worker_pool.cc
diff --git a/cc/raster/zero_copy_tile_task_worker_pool.cc b/cc/raster/zero_copy_tile_task_worker_pool.cc
index 147eeca64f82f5d9f8848bd725273e24df830b2f..c96399c5e92473ffd585a5d72c8a6f87ebd23d8c 100644
--- a/cc/raster/zero_copy_tile_task_worker_pool.cc
+++ b/cc/raster/zero_copy_tile_task_worker_pool.cc
@@ -65,22 +65,25 @@ scoped_ptr<TileTaskWorkerPool> ZeroCopyTileTaskWorkerPool::Create(
     base::SequencedTaskRunner* task_runner,
     TaskGraphRunner* task_graph_runner,
     ResourceProvider* resource_provider,
-    bool use_rgba_4444_texture_format) {
+    ResourceFormat memory_efficient_format,
+    ResourceFormat memory_efficient_format_with_alpha) {
   return make_scoped_ptr<TileTaskWorkerPool>(new ZeroCopyTileTaskWorkerPool(
       task_runner, task_graph_runner, resource_provider,
-      use_rgba_4444_texture_format));
+      memory_efficient_format, memory_efficient_format_with_alpha));
 }
 
 ZeroCopyTileTaskWorkerPool::ZeroCopyTileTaskWorkerPool(
     base::SequencedTaskRunner* task_runner,
     TaskGraphRunner* task_graph_runner,
     ResourceProvider* resource_provider,
-    bool use_rgba_4444_texture_format)
+    ResourceFormat memory_efficient_format,
+    ResourceFormat memory_efficient_format_with_alpha)
     : 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),
+      memory_efficient_format_(memory_efficient_format),
+      memory_efficient_format_with_alpha_(memory_efficient_format_with_alpha),
       task_set_finished_weak_ptr_factory_(this) {}
 
 ZeroCopyTileTaskWorkerPool::~ZeroCopyTileTaskWorkerPool() {
@@ -183,9 +186,13 @@ void ZeroCopyTileTaskWorkerPool::CheckForCompletedTasks() {
 
 ResourceFormat ZeroCopyTileTaskWorkerPool::GetResourceFormat(
     bool must_support_alpha) const {
-  return use_rgba_4444_texture_format_
-             ? RGBA_4444
-             : resource_provider_->best_texture_format();
+  if (memory_efficient_format_with_alpha_ != RGBA_8888 && must_support_alpha)
+    return memory_efficient_format_with_alpha_;
+
+  if (memory_efficient_format_ != RGBA_8888 && !must_support_alpha)
+    return memory_efficient_format_;
+
+  return resource_provider_->best_texture_format();
 }
 
 bool ZeroCopyTileTaskWorkerPool::GetResourceRequiresSwizzle(