Expose synthetic delays through the GPU benchmarking extension

components/tracing/child_trace_message_filter.h

Index: components/tracing/child_trace_message_filter.h
diff --git a/components/tracing/child_trace_message_filter.h b/components/tracing/child_trace_message_filter.h
index cbd300f38b01297921c961d9f2bd6a2ae01b94d4..65db27f3a345e385f29d19fe21a76c4f52aa44f9 100644
--- a/components/tracing/child_trace_message_filter.h
+++ b/components/tracing/child_trace_message_filter.h
@@ -9,6 +9,8 @@
 #include "base/memory/ref_counted_memory.h"
 #include "ipc/ipc_channel_proxy.h"
 
+struct TracingMsg_ConfigureSyntheticDelay_Params;
+
 namespace base {
 class MessageLoopProxy;
 }
@@ -43,6 +45,8 @@ class ChildTraceMessageFilter : public IPC::ChannelProxy::MessageFilter {
   void OnSetWatchEvent(const std::string& category_name,
                        const std::string& event_name);
   void OnCancelWatchEvent();
+  void OnConfigureSyntheticDelay(
+      const TracingMsg_ConfigureSyntheticDelay_Params& params);
 
   // Callback from trace subsystem.
   void OnTraceDataCollected(