Move Singleton and related structs to namespace base

components/service_tab_launcher/browser/android/service_tab_launcher.cc

 // Copyright 2015 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 "components/service_tab_launcher/browser/android/service_tab_launcher.h"
 
 #include "base/android/jni_string.h"
 #include "base/callback.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/page_navigator.h"
 #include "content/public/browser/web_contents.h"
 #include "jni/ServiceTabLauncher_jni.h"
 
 using base::android::AttachCurrentThread;
 using base::android::ConvertUTF8ToJavaString;
 using base::android::GetApplicationContext;
 
 // Called by Java when the WebContents instance for a request Id is available.
 void OnWebContentsForRequestAvailable(
     JNIEnv* env, jclass clazz, jint request_id, jobject android_web_contents) {
   service_tab_launcher::ServiceTabLauncher::GetInstance()->OnTabLaunched(
       request_id,
       content::WebContents::FromJavaWebContents(android_web_contents));
 }
 
 namespace service_tab_launcher {
 
 // static
 ServiceTabLauncher* ServiceTabLauncher::GetInstance() {
-  return Singleton<ServiceTabLauncher>::get();
+  return base::Singleton<ServiceTabLauncher>::get();
 }
 
 ServiceTabLauncher::ServiceTabLauncher() {
   java_object_.Reset(
       Java_ServiceTabLauncher_getInstance(AttachCurrentThread(),
                                           GetApplicationContext()));
 }
 
 ServiceTabLauncher::~ServiceTabLauncher() {}
 
@@ skipping 51 matching lines @@
     callback->Run(web_contents);
 
   tab_launched_callbacks_.Remove(request_id);
 }
 
 bool ServiceTabLauncher::RegisterServiceTabLauncher(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace service_tab_launcher