DevTools: expose setLayerTreeId() so we can relate events from LayerTreeHost

Source/core/inspector/InspectorTimelineAgent.h

 /*
 * Copyright (C) 2012 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
@@ skipping 103 matching lines @@
 
     ~InspectorTimelineAgent();
 
     virtual void setFrontend(InspectorFrontend*);
     virtual void clearFrontend();
     virtual void restore();
 
     virtual void start(ErrorString*, const int* maxCallStackDepth, const bool* includeDomCounters, const bool* includeNativeMemoryStatistics);
     virtual void stop(ErrorString*);
 
+    void setLayerTreeId(int layerTreeId) { m_layerTreeId = layerTreeId; }
+    int layerTreeId() const { return m_layerTreeId; }
     int id() const { return m_id; }
 
     void didCommitLoad();
 
     // Methods called from WebCore.
     bool willCallFunction(ScriptExecutionContext* context, const String& scriptName, int scriptLine);
     void didCallFunction();
 
     bool willDispatchEvent(Document* document, const Event& event, DOMWindow* window, Node* node, const EventPath& eventPath);
     bool willDispatchEventOnWindow(const Event& event, DOMWindow* window);
@@ skipping 144 matching lines @@
     typedef Vector<GCEvent> GCEvents;
     GCEvents m_gcEvents;
     int m_maxCallStackDepth;
     unsigned m_platformInstrumentationClientInstalledAtStackDepth;
     RefPtr<JSONObject> m_pendingFrameRecord;
     InspectorType m_inspectorType;
     InspectorClient* m_client;
     WeakPtrFactory<InspectorTimelineAgent> m_weakFactory;
     RefPtr<TimelineTraceEventProcessor> m_traceEventProcessor;
     unsigned m_styleRecalcElementCounter;
+    int m_layerTreeId;
 };
 
 } // namespace WebCore
 
 #endif // !defined(InspectorTimelineAgent_h)