Add the swap size to the PostSubBuffer trace event

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 41ec8c1d4a366e9a973b9e31c646176d6f265eb7..3958c9547bd54769cc05bdd2b6df2b602354a3c8 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -3075,7 +3075,8 @@ void GLES2Implementation::PostSubBufferCHROMIUM(
   GPU_CLIENT_SINGLE_THREAD_CHECK();
   GPU_CLIENT_LOG("[" << GetLogPrefix() << "] PostSubBufferCHROMIUM("
       << x << ", " << y << ", " << width << ", " << height << ")");
-  TRACE_EVENT0("gpu", "GLES2::PostSubBufferCHROMIUM");
+  TRACE_EVENT2("gpu", "GLES2::PostSubBufferCHROMIUM",
+               "width", width, "height", height);
 
   // Same flow control as GLES2Implementation::SwapBuffers (see comments there).
   swap_buffers_tokens_.push(helper_->InsertToken());