| Index: Source/core/frame/FrameClient.h | 
| diff --git a/Source/core/frame/FrameClient.h b/Source/core/frame/FrameClient.h | 
| index 945c71419481175f0671a72c7d2285018c169c87..a6f68b0519caf0bdeaf1ad87bf777e51144a7188 100644 | 
| --- a/Source/core/frame/FrameClient.h | 
| +++ b/Source/core/frame/FrameClient.h | 
| @@ -34,6 +34,8 @@ public: | 
| virtual Frame* firstChild() const = 0; | 
| virtual Frame* lastChild() const = 0; | 
|  | 
| +    virtual unsigned backForwardLength() = 0; | 
| + | 
| // Returns true if the embedder intercepted the postMessage call | 
| virtual bool willCheckAndDispatchMessageEvent(SecurityOrigin* /*target*/, MessageEvent*, LocalFrame* /*sourceFrame*/) const { return false; } | 
|  | 
|  |