gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/service/async_pixel_transfer_manager_idle.cc

Index: gpu/command_buffer/service/async_pixel_transfer_manager_idle.cc
diff --git a/gpu/command_buffer/service/async_pixel_transfer_manager_idle.cc b/gpu/command_buffer/service/async_pixel_transfer_manager_idle.cc
index 88aff575b0816edcf20b692ced4140029b63f497..18bf2441c9e8144e34f834e25be68d62e0ce796f 100644
--- a/gpu/command_buffer/service/async_pixel_transfer_manager_idle.cc
+++ b/gpu/command_buffer/service/async_pixel_transfer_manager_idle.cc
@@ -283,6 +283,13 @@ void AsyncPixelTransferManagerIdle::BindCompletedAsyncTransfers() {
   // Everything is already bound.
 }
 
+void AsyncPixelTransferManagerIdle::AsyncRunWhenCompleted(
+    base::Callback<void()> callback) {
+  shared_state_.tasks.push_back(
+      Task(0,  // 0 transfer_id for notification tasks.
+           base::Bind(callback)));
+}
+
 void AsyncPixelTransferManagerIdle::AsyncNotifyCompletion(
     const AsyncMemoryParams& mem_params,
     AsyncPixelTransferCompletionObserver* observer) {