Add synthetic delay points for latency testing

gpu/command_buffer/service/async_pixel_transfer_manager_egl.h

Index: gpu/command_buffer/service/async_pixel_transfer_manager_egl.h
diff --git a/gpu/command_buffer/service/async_pixel_transfer_manager_egl.h b/gpu/command_buffer/service/async_pixel_transfer_manager_egl.h
index 4c273fe7f52aeb287b532361e8e43dc26066b0d2..435d82595f6c73e90cfbc89a40ef978862529f0a 100644
--- a/gpu/command_buffer/service/async_pixel_transfer_manager_egl.h
+++ b/gpu/command_buffer/service/async_pixel_transfer_manager_egl.h
@@ -6,6 +6,7 @@
 #define GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_MANAGER_EGL_H_
 
 #include "gpu/command_buffer/service/async_pixel_transfer_manager.h"
+#include "base/atomic_ref_count.h"
 
 #include "base/memory/ref_counted.h"
 
@@ -39,6 +40,7 @@ class AsyncPixelTransferManagerEGL : public AsyncPixelTransferManager {
     typedef std::list<base::WeakPtr<AsyncPixelTransferDelegateEGL> >
         TransferQueue;
     TransferQueue pending_allocations;
+    base::AtomicRefCount pending_uploads;
   };
 
  private: