content: remove unimplemented function prototype

This declaration exists in the header, but it has no definition
nor callers.

Review URL: http://codereview.chromium.org/7583039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@95855 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/render_message_filter.h

@@ -126,11 +126,6 @@ class RenderMessageFilter : public BrowserMessageFilter {
   void OnCookiesEnabled(const GURL& url,
                         const GURL& first_party_for_cookies,
                         bool* cookies_enabled);
-  void OnPluginFileDialog(const IPC::Message& msg,
-                          bool multiple_files,
-                          const std::wstring& title,
-                          const std::wstring& filter,
-                          uint32 user_data);
 
 #if defined(OS_MACOSX)
   void OnLoadFont(const FontDescriptor& font,