[Invalidation Tracking] Add trace events for compositor based invalidations

Source/core/inspector/InspectorTraceEvents.h

Index: Source/core/inspector/InspectorTraceEvents.h
diff --git a/Source/core/inspector/InspectorTraceEvents.h b/Source/core/inspector/InspectorTraceEvents.h
index 7f088b6fbc3e2388d55296fb43d7cc0ae18c7a3c..e5e5c10a7504234f8df3c5abda7a990a5df4a2f0 100644
--- a/Source/core/inspector/InspectorTraceEvents.h
+++ b/Source/core/inspector/InspectorTraceEvents.h
@@ -20,8 +20,9 @@ class GraphicsLayer;
 class KURL;
 class LayoutRect;
 class LocalFrame;
-class RenderObject;
 class RenderImage;
+class RenderLayer;
+class RenderObject;
 class ResourceRequest;
 class ResourceResponse;
 class ScriptSourceCode;
@@ -100,6 +101,24 @@ public:
     static PassRefPtr<TraceEvent::ConvertableToTraceFormat> data(ExecutionContext*, XMLHttpRequest*);
 };
 
+class InspectorLayerInvalidationTrackingEvent {
+public:
+    static const char SquashingLayerGeometryWasUpdated[];
+    static const char AddedToSquashingLayer[];
+    static const char RemovedFromSquashingLayer[];
+    static const char ReflectionLayerChanged[];
+    static const char NewCompositedLayer[];
+    static const char AncestorRequiresNewLayer[];
+
+    static PassRefPtr<TraceEvent::ConvertableToTraceFormat> data(const RenderLayer*, const char* reason);
+};
+#define TRACE_LAYER_INVALIDATION(LAYER, REASON) \
+    TRACE_EVENT_INSTANT1( \
+        TRACE_DISABLED_BY_DEFAULT("devtools.timeine.invalidationTracking"), \
+        "LayerInvalidationTracking", \
+        "data", \
+        InspectorLayerInvalidationTrackingEvent::data((LAYER), (REASON)))
+
 class InspectorPaintEvent {
 public:
     static PassRefPtr<TraceEvent::ConvertableToTraceFormat> data(RenderObject*, const LayoutRect& clipRect, const GraphicsLayer*);