Implement RevokePermission() method in PermissionService.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 61f6a2688053dbf1f3a510ae7d2305833d11adfe..b2ad7c8a22e9d9f2becf9fd4e06d30ed6678415f 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -449,6 +449,11 @@ class CONTENT_EXPORT ContentBrowserClient {
       const GURL& requesting_origin,
       const GURL& embedding_origin);
 
+  virtual void ResetPermission(PermissionType permission,
+                               BrowserContext* browser_context,
+                               const GURL& requesting_origin,
+                               const GURL& embedding_origin) {}
+
   // Returns true if the given page is allowed to open a window of the given
   // type. If true is returned, |no_javascript_access| will indicate whether
   // the window that is created should be scriptable/in the same process.