Support merged Dart-JS callstacks

Source/bindings/v8/DebuggerScript.js

Index: Source/bindings/v8/DebuggerScript.js
diff --git a/Source/bindings/v8/DebuggerScript.js b/Source/bindings/v8/DebuggerScript.js
index 6973cf6979e689692351885792a66a9681c22f36..bb85fad490adad427b5c3745606010fea9523e2b 100644
--- a/Source/bindings/v8/DebuggerScript.js
+++ b/Source/bindings/v8/DebuggerScript.js
@@ -351,6 +351,7 @@ DebuggerScript._frameMirrorToJSCallFrame = function(frameMirror, callerFrame, sc
     var thisObject = frameDetails.receiver();
 
     var isAtReturn = !!frameDetails.isAtReturn();
+    var cachedFramePointer = frameDetails.framePointer();
     var returnValue = isAtReturn ? frameDetails.returnValue() : undefined;
 
     var scopeMirrors = (scopeDetailsLevel === DebuggerScript.ScopeInfoDetails.NoScopes ? [] : frameMirror.allScopes(scopeDetailsLevel === DebuggerScript.ScopeInfoDetails.FastAsyncScopes));
@@ -434,6 +435,10 @@ DebuggerScript._frameMirrorToJSCallFrame = function(frameMirror, callerFrame, sc
         return scriptId;
     }
 
+    function framePointer() {
+        return cachedFramePointer;
+    }
+
     function functionName()
     {
         // FIXMEDART: remove caching when Dart devtools refactor CL lands.
@@ -501,6 +506,7 @@ DebuggerScript._frameMirrorToJSCallFrame = function(frameMirror, callerFrame, sc
         "setVariableValue": setVariableValue,
         "stepInPositions": stepInPositions,
         "isAtReturn": isAtReturn,
+        "framePointer": framePointer,
         "returnValue": returnValue
     };
 }