cc, gpu: Use RGBA when using msaa on systems that don't support BGRA

cc/raster/gpu_tile_task_worker_pool.cc

Index: cc/raster/gpu_tile_task_worker_pool.cc
diff --git a/cc/raster/gpu_tile_task_worker_pool.cc b/cc/raster/gpu_tile_task_worker_pool.cc
index 3de7118a05d16889b3d295a3f3b1f1af6c03a9d1..454e9b40b25efc209ce3b9540498206f072937b5 100644
--- a/cc/raster/gpu_tile_task_worker_pool.cc
+++ b/cc/raster/gpu_tile_task_worker_pool.cc
@@ -208,7 +208,7 @@ void GpuTileTaskWorkerPool::CheckForCompletedTasks() {
 }
 
 ResourceFormat GpuTileTaskWorkerPool::GetResourceFormat() {
-  return rasterizer_->resource_provider()->best_texture_format();
+  return rasterizer_->resource_provider()->best_render_buffer_format();
 }
 
 void GpuTileTaskWorkerPool::CompleteTasks(const Task::Vector& tasks) {