Do not show "Add to Home Screen" info bar if WebAPK is installed

chrome/browser/android/banners/app_banner_data_fetcher_android.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_DATA_FETCHER_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_DATA_FETCHER_ANDROID_H_
 
 #include "base/android/jni_android.h"
 #include "base/callback_forward.h"
 #include "base/macros.h"
@@ skipping 25 matching lines @@
   base::Closure FetchWebappSplashScreenImageCallback(
       const std::string& webapp_id);
 
  protected:
   ~AppBannerDataFetcherAndroid() override;
 
   std::string GetBannerType() override;
   std::string GetAppIdentifier() override;
 
  private:
+  bool IsWebAppInstalled(content::BrowserContext* browser_context,
+                         const GURL& start_url) override;
+
   void ShowBanner(const GURL& icon_url,
                   const SkBitmap* icon,
                   const base::string16& title,
                   const std::string& referrer) override;
 
   base::android::ScopedJavaGlobalRef<jobject> native_app_data_;
   std::string native_app_package_;
 
   int ideal_splash_image_size_in_dp_;
   int minimum_splash_image_size_in_dp_;
 
   DISALLOW_COPY_AND_ASSIGN(AppBannerDataFetcherAndroid);
 };
 
 }  // namespace banners
 
 #endif  // CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_DATA_FETCHER_ANDROID_H_