Update to Chromium revision 68623971 (#403382)

libcef/browser/extensions/extensions_browser_client.cc

@@ -170,12 +170,6 @@ bool CefExtensionsBrowserClient::IsLoggedInAsPublicAccount()  {
   return false;
 }
 
-ApiActivityMonitor* CefExtensionsBrowserClient::GetApiActivityMonitor(
-    BrowserContext* context) {
-  // CEF doesn't monitor API function calls or events.
-  return NULL;
-}
-
 ExtensionSystemProvider*
 CefExtensionsBrowserClient::GetExtensionSystemFactory() {
   return CefExtensionSystemFactory::GetInstance();