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 9fc6cdd513c5c751d51eae13487596d09ef45d6a..d2ae7a0dd59c07dd4157d4eb2683965cb4bb539e 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -450,6 +450,11 @@ 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.