Add synthetic delay points for latency testing

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 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/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <list>
 #include <map>
 #include <stack>
 #include <string>
 #include <vector>
 
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
+#include "base/debug/trace_event_synthetic_delay.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "build/build_config.h"
 #define GLES2_GPU_SERVICE 1
 #include "gpu/command_buffer/common/debug_marker_manager.h"
 #include "gpu/command_buffer/common/gles2_cmd_format.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "gpu/command_buffer/common/id_allocator.h"
 #include "gpu/command_buffer/common/mailbox.h"
@@ skipping 8907 matching lines @@
   int this_frame_number = frame_number_++;
   // TRACE_EVENT for gpu tests:
   TRACE_EVENT_INSTANT2("test_gpu", "SwapBuffersLatency",
                        TRACE_EVENT_SCOPE_THREAD,
                        "GLImpl", static_cast<int>(gfx::GetGLImplementation()),
                        "width", (is_offscreen ? offscreen_size_.width() :
                                  surface_->GetSize().width()));
   TRACE_EVENT2("gpu", "GLES2DecoderImpl::DoSwapBuffers",
                "offscreen", is_offscreen,
                "frame", this_frame_number);
+  {
+    TRACE_EVENT_SYNTHETIC_DELAY("gpu.SwapBuffers");
+  }
+
   bool is_tracing;
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("gpu.debug"),
                                      &is_tracing);
   if (is_tracing) {
     ScopedFrameBufferBinder binder(this, GetBackbufferServiceId());
     gpu_state_tracer_->TakeSnapshotWithCurrentFramebuffer(
         is_offscreen ? offscreen_size_ : surface_->GetSize());
   }
 
   // If offscreen then don't actually SwapBuffers to the display. Just copy
@@ skipping 1680 matching lines @@
   DoDidUseTexImageIfNeeded(texture, texture->target());
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu