Issue #188:

- Add a CefV8Context object and CefV8Value::ExecuteFunctionWithContext method to support asynchronous V8 ExecuteFunction callbacks.
- Add a CefFrame::GetBrowser() method.
- Ensure that V8 types are only referenced on the UI thread.
- Accept a empty |object| parameter to CefV8Value::ExecuteFunction.

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@188 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser_impl.h

@@ -349,6 +349,7 @@ public:
   virtual bool IsFocused();
   virtual CefString GetName() { return name_; }
   virtual CefString GetURL() { return browser_->GetURL(this); }
+  virtual CefRefPtr<CefBrowser> GetBrowser() { return browser_.get(); }
 
 private:
   CefRefPtr<CefBrowserImpl> browser_;