Support Promises event-based instrumentation on backend.

Source/bindings/core/v8/ScriptDebugServer.h

Index: Source/bindings/core/v8/ScriptDebugServer.h
diff --git a/Source/bindings/core/v8/ScriptDebugServer.h b/Source/bindings/core/v8/ScriptDebugServer.h
index 2412254c4a799e31767d8298e8317f470bfbd34c..756ef38babaf60ff0b2ff7590d8fd07e27d185e1 100644
--- a/Source/bindings/core/v8/ScriptDebugServer.h
+++ b/Source/bindings/core/v8/ScriptDebugServer.h
@@ -156,6 +156,8 @@ private:
 
     void handleV8AsyncTaskEvent(ScriptDebugListener*, ScriptState* pausedScriptState, v8::Handle<v8::Object> executionState, v8::Handle<v8::Object> eventData);
 
+    void handleV8PromiseEvent(ScriptDebugListener*, ScriptState* pausedScriptState, v8::Handle<v8::Object> executionState, v8::Handle<v8::Object> eventData);
+
     bool m_runningNestedMessageLoop;
 };