Convert app banners to use Mojo.

third_party/WebKit/Source/modules/app_banner/AppBannerPromptResult.cpp

 // 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 "modules/app_banner/AppBannerPromptResult.h"
 
 #include "public/platform/modules/app_banner/WebAppBannerPromptResult.h"
 
 namespace blink {
 
 AppBannerPromptResult::~AppBannerPromptResult() {}
 
 String AppBannerPromptResult::outcome() const {
   switch (m_outcome) {
     case WebAppBannerPromptResult::Outcome::Accepted:
       return "accepted";
 
     case WebAppBannerPromptResult::Outcome::Dismissed:
       return "dismissed";
   }
 
   ASSERT_NOT_REACHED();
   return "";
 }
 
 AppBannerPromptResult::AppBannerPromptResult(
-    const AtomicString& platform,
+    const String& platform,
     WebAppBannerPromptResult::Outcome outcome)
     : m_platform(platform), m_outcome(outcome) {}
 
 }  // namespace blink