Create MetricsPrivateDelegate for metricsPrivate behavior

extensions/shell/browser/shell_extensions_api_client.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/shell/browser/shell_extensions_api_client.h"
 
+#include "base/memory/ptr_util.h"
+#include "extensions/shell/browser/api/metrics_private/shell_metrics_private_delegate.h"
 #include "extensions/shell/browser/shell_app_view_guest_delegate.h"
 #include "extensions/shell/browser/shell_extension_web_contents_observer.h"
 
 namespace extensions {
 
-ShellExtensionsAPIClient::ShellExtensionsAPIClient() {
-}
+ShellExtensionsAPIClient::ShellExtensionsAPIClient() {}
+
+ShellExtensionsAPIClient::~ShellExtensionsAPIClient() {}
 
 void ShellExtensionsAPIClient::AttachWebContentsHelpers(
     content::WebContents* web_contents) const {
   ShellExtensionWebContentsObserver::CreateForWebContents(web_contents);
 }
 
 AppViewGuestDelegate* ShellExtensionsAPIClient::CreateAppViewGuestDelegate()
     const {
   return new ShellAppViewGuestDelegate();
 }
 
+MetricsPrivateDelegate* ShellExtensionsAPIClient::GetMetricsPrivateDelegate() {
+  if (!metrics_private_delegate_)
+    metrics_private_delegate_.reset(new ShellMetricsPrivateDelegate());
+  return metrics_private_delegate_.get();
+}
+
 }  // namespace extensions