Add synthetic delay points for latency testing

gpu/command_buffer/service/async_pixel_transfer_manager_egl.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 "gpu/command_buffer/service/async_pixel_transfer_manager_egl.h"
 
 #include <list>
 #include <string>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
+#include "base/debug/trace_event_synthetic_delay.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
 #include "gpu/command_buffer/service/async_pixel_transfer_delegate.h"
 #include "gpu/command_buffer/service/safe_shared_memory_pool.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_surface_egl.h"
 #include "ui/gl/scoped_binders.h"
@@ skipping 205 matching lines @@
     // GPU action that needs to occur. We could use fences and try
     // to do this less often. However, on older drivers fences are
     // not always reliable (eg. Mali-400 just blocks forever).
     if (wait_for_uploads_) {
       TRACE_EVENT0("gpu", "glFinish");
       glFinish();
     }
   }
 
   void MarkAsTransferIsInProgress() {
+    TRACE_EVENT_SYNTHETIC_DELAY_BEGIN("gpu.AsyncTexImage");
     transfer_completion_.Reset();
   }
 
   void MarkAsCompleted() {
+    TRACE_EVENT_SYNTHETIC_DELAY_END("gpu.AsyncTexImage");
     transfer_completion_.Signal();
   }
 
   void WaitForTransferCompletion() {
     TRACE_EVENT0("gpu", "WaitForTransferCompletion");
     // TODO(backer): Deschedule the channel rather than blocking the main GPU
     // thread (crbug.com/240265).
     transfer_completion_.Wait();
   }
 
@@ skipping 514 matching lines @@
 
 AsyncPixelTransferDelegate*
 AsyncPixelTransferManagerEGL::CreatePixelTransferDelegateImpl(
     gles2::TextureRef* ref,
     const AsyncTexImage2DParams& define_params) {
   return new AsyncPixelTransferDelegateEGL(
       &shared_state_, ref->service_id(), define_params);
 }
 
 }  // namespace gpu