Support merged Dart-JS callstacks

Source/bindings/dart/DartDOMData.h

Index: Source/bindings/dart/DartDOMData.h
diff --git a/Source/bindings/dart/DartDOMData.h b/Source/bindings/dart/DartDOMData.h
index 8cf78cf25c6dfcf6b41deceee43021aaa570f953..ba00d38e7067169966d5806e60c51c75ed95e1ea 100644
--- a/Source/bindings/dart/DartDOMData.h
+++ b/Source/bindings/dart/DartDOMData.h
@@ -34,6 +34,7 @@
 #include "DartJsInteropData.h"
 #include "DartWebkitClassIds.h"
 
+#include "bindings/common/StackTrace.h"
 #include "bindings/dart/DartCustomElementBinding.h"
 #include "bindings/dart/DartLibraryIds.h"
 #include "bindings/dart/DartScriptState.h"
@@ -81,9 +82,10 @@ public:
     ExecutionContext* scriptExecutionContext() { return m_scriptExecutionContext; }
     bool isDOMEnabled() { return m_isDOMEnabled; }
 
-    // We track the Dart specific recursion level here as well as the global
-    // recursion level tracked by m_recursionScope due to dartbug.com/14183.
-    int* recursion() { return &m_recursion; }
+    // Track Dart stack trace depth and timestamp pairs so that we can
+    // correctly interleave Dart and JavaScript stack traces.
+    StackTraceTimestampTracker* stackTraceTimestampTracker() { return &m_stackTraceTimestampTracker; }
+
     DartStringCache& stringCache() { return m_stringCache; }
 
     void setThreadSafeIsolateWrapper(PassRefPtr<ThreadSafeDartIsolateWrapper>);
@@ -235,6 +237,7 @@ private:
     ExecutionContext* m_scriptExecutionContext;
     bool m_isDOMEnabled;
     int m_recursion;
+    StackTraceTimestampTracker m_stackTraceTimestampTracker;
     DartStringCache m_stringCache;
     RefPtr<ThreadSafeDartIsolateWrapper> m_threadSafeIsolateWrapper;
     Mutex m_isolateWrapperMutex;