Move RequestPpapiBrokerPermission from WebContentsObserver to WebContentsDelegate.

content/public/browser/web_contents_observer.cc

Index: content/public/browser/web_contents_observer.cc
diff --git a/content/public/browser/web_contents_observer.cc b/content/public/browser/web_contents_observer.cc
index f40db1d45666c687283ef420f37e7feecff8e909..14790293040c0f89c1893579653e5b9d1ca9ac39 100644
--- a/content/public/browser/web_contents_observer.cc
+++ b/content/public/browser/web_contents_observer.cc
@@ -37,14 +37,6 @@ void WebContentsObserver::Observe(WebContents* web_contents) {
   }
 }
 
-bool WebContentsObserver::RequestPpapiBrokerPermission(
-    WebContents* web_contents,
-    const GURL& url,
-    const FilePath& plugin_path,
-    const base::Callback<void(bool)>& callback) {
-  return false;
-}
-
 bool WebContentsObserver::OnMessageReceived(const IPC::Message& message) {
   return false;
 }