Implement "appinstalled" event on Android.

chrome/browser/banners/app_banner_manager.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_BANNERS_APP_BANNER_MANAGER_H_
 #define CHROME_BROWSER_BANNERS_APP_BANNER_MANAGER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 50 matching lines @@
   // Sets the total engagement required for triggering the banner in testing.
   static void SetTotalEngagementToTrigger(double engagement);
 
   // Returns whether or not the URLs match for everything except for the ref.
   static bool URLsAreForTheSamePage(const GURL& first, const GURL& second);
 
   // Requests an app banner. If |is_debug_mode| is true, any failure in the
   // pipeline will be reported to the devtools console.
   virtual void RequestAppBanner(const GURL& validated_url, bool is_debug_mode);
 
+  // Informs the page that it has been installed via an app banner.
+  // This is redundant for the beforeinstallprompt event's promise being
+  // resolved, but is required by the install event spec.
+  void OnInstall();
+
   // Sends a message to the renderer that the user accepted the banner. Does
   // nothing if |request_id| does not match the current request.
   void SendBannerAccepted(int request_id);
 
   // Sends a message to the renderer that the user dismissed the banner. Does
   // nothing if |request_id| does not match the current request.
   void SendBannerDismissed(int request_id);
 
   // Overridden and passed through base::Bind on desktop platforms. Called when
   // the bookmark app install initiated by a banner has completed. Not used on
@@ skipping 188 matching lines @@
   // scoped to the WebContents which they are observing. This allows us to use
   // weak pointers for callbacks.
   base::WeakPtrFactory<AppBannerManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AppBannerManager);
 };
 
 }  // namespace banners
 
 #endif  // CHROME_BROWSER_BANNERS_APP_BANNER_MANAGER_H_