DevTools: Show GPU utilization bar on timeline

Source/core/inspector/TimelineTraceEventProcessor.h

Index: Source/core/inspector/TimelineTraceEventProcessor.h
diff --git a/Source/core/inspector/TimelineTraceEventProcessor.h b/Source/core/inspector/TimelineTraceEventProcessor.h
index 8b4d99d5c114c106b72337f580c04d6fdd76cd75..5483d1e496ec5d61bc1602a425c54cbc2079909b 100644
--- a/Source/core/inspector/TimelineTraceEventProcessor.h
+++ b/Source/core/inspector/TimelineTraceEventProcessor.h
@@ -219,6 +219,8 @@ private:
     void onLayerDeleted(const TraceEvent&);
     void onDrawLazyPixelRef(const TraceEvent&);
     void onLazyPixelRefDeleted(const TraceEvent&);
+    void onGPUTaskBegin(const TraceEvent&);
+    void onGPUTaskEnd(const TraceEvent&);
 
     WeakPtr<InspectorTimelineAgent> m_timelineAgent;
     TimelineTimeConverter m_timeConverter;
@@ -240,6 +242,7 @@ private:
     unsigned long long m_layerId;
     double m_paintSetupStart;
     double m_paintSetupEnd;
+    RefPtr<JSONObject> m_gpuTask;
 
     struct ImageInfo {
         int backendNodeId;