[not for review] Add Draw entries to window Performance Timeline

Source/core/timing/PerformanceEntry.h

Index: Source/core/timing/PerformanceEntry.h
diff --git a/Source/core/timing/PerformanceEntry.h b/Source/core/timing/PerformanceEntry.h
index 117d994c615fb08daa312d8020e51ca97875c7b6..14c01c8ff7a534bd224d0af7d5cd58902d83dc62 100644
--- a/Source/core/timing/PerformanceEntry.h
+++ b/Source/core/timing/PerformanceEntry.h
@@ -50,6 +50,7 @@ public:
     double duration() const;
 
     virtual bool isResource() { return false; }
+    virtual bool isDraw() { return false; }
     virtual bool isMark() { return false; }
     virtual bool isMeasure() { return false; }