Add a gpu.SwapBuffers synthetic delay to PostSubBuffer.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index a886513fb9bf4a2d4cdb748096cf9f9e39322e34..f21e78b414f118dc19fb7522131354cc0ecf8dd8 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -7547,6 +7547,9 @@ error::Error GLES2DecoderImpl::HandlePixelStorei(
 error::Error GLES2DecoderImpl::HandlePostSubBufferCHROMIUM(
     uint32 immediate_data_size, const cmds::PostSubBufferCHROMIUM& c) {
   TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandlePostSubBufferCHROMIUM");
+  {
+    TRACE_EVENT_SYNTHETIC_DELAY("gpu.SwapBuffers");

[Zhenyao Mo, 2014/04/17 20:45:48]

I feel you should use a different name from "gpu.SwapBuffers", like
"gpu.PostSubBuffer".  You may have to set the time for the new name in several
places, but in the long run, this avoids any unexpected side-effects /confusion
in the future.

+  }
   if (!supports_post_sub_buffer_) {
     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,