Add navigation controls to DevTools screencast view

Source/core/inspector/InspectorPageAgent.h

Index: Source/core/inspector/InspectorPageAgent.h
diff --git a/Source/core/inspector/InspectorPageAgent.h b/Source/core/inspector/InspectorPageAgent.h
index 38d255f15df1d18bca025fbae47f4295ce96a8cb..8ae27214c2a50c0773dc13982a39f3530bf9c73d 100644
--- a/Source/core/inspector/InspectorPageAgent.h
+++ b/Source/core/inspector/InspectorPageAgent.h
@@ -93,6 +93,8 @@ public:
     virtual void removeScriptToEvaluateOnLoad(ErrorString*, const String& identifier);
     virtual void reload(ErrorString*, const bool* optionalIgnoreCache, const String* optionalScriptToEvaluateOnLoad, const String* optionalScriptPreprocessor);
     virtual void navigate(ErrorString*, const String& url);
+    virtual void getNavigationHistory(ErrorString*, int*, RefPtr<TypeBuilder::Array<TypeBuilder::Page::NavigationEntry> >&);
+    virtual void navigateToHistoryEntry(ErrorString*, int);
     virtual void getCookies(ErrorString*, RefPtr<TypeBuilder::Array<TypeBuilder::Page::Cookie> >& cookies, WTF::String* cookiesString);
     virtual void deleteCookie(ErrorString*, const String& cookieName, const String& url);
     virtual void getResourceTree(ErrorString*, RefPtr<TypeBuilder::Page::FrameResourceTree>&);