[Extensions] Short-circuit activity logging if not enabled

extensions/shell/browser/shell_extensions_browser_client.cc

Index: extensions/shell/browser/shell_extensions_browser_client.cc
diff --git a/extensions/shell/browser/shell_extensions_browser_client.cc b/extensions/shell/browser/shell_extensions_browser_client.cc
index 85204a351857e46cc311dcfec1255424465429df..2ad6c8df21112dec7ce89191458ab49cdf846420 100644
--- a/extensions/shell/browser/shell_extensions_browser_client.cc
+++ b/extensions/shell/browser/shell_extensions_browser_client.cc
@@ -167,12 +167,6 @@ bool ShellExtensionsBrowserClient::IsLoggedInAsPublicAccount() {
   return false;
 }
 
-ApiActivityMonitor* ShellExtensionsBrowserClient::GetApiActivityMonitor(
-    BrowserContext* context) {
-  // app_shell doesn't monitor API function calls or events.
-  return NULL;
-}
-
 ExtensionSystemProvider*
 ShellExtensionsBrowserClient::GetExtensionSystemFactory() {
   return ShellExtensionSystemFactory::GetInstance();