Use heuristic to work out when to prompt for app install banners.

chrome/browser/android/banners/app_banner_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_MANAGER_H_
 #define CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_MANAGER_H_
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_weak_ref.h"
 #include "base/memory/ref_counted.h"
@@ skipping 120 matching lines @@
   // process of showing a banner for the package designated by |tag_content| on
   // the page at the |expected_url|.
   void OnDidRetrieveMetaTagContent(bool success,
                                    const std::string& tag_name,
                                    const std::string& tag_content,
                                    const GURL& expected_url);
 
   // Called when the result of the CheckHasServiceWorker query has completed.
   void OnDidCheckHasServiceWorker(bool has_service_worker);
 
+  // Record that the banner could be shown at this point, if the triggering
+  // heuristic allowed.
+  void RecordCouldShowBanner(const std::string& package_or_start_url);
+
+  // Check if the banner should be shown.
+  bool CheckIfShouldShow(const std::string& package_or_start_url);
+
   // Fetches the icon for an app.
   scoped_ptr<chrome::BitmapFetcher> fetcher_;
   GURL validated_url_;
   GURL app_icon_url_;
 
   base::string16 app_title_;
   scoped_ptr<SkBitmap> app_icon_;
 
   content::Manifest web_app_data_;
 
@@ skipping 10 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(AppBannerManager);
 };  // class AppBannerManager
 
 // Register native methods
 bool RegisterAppBannerManager(JNIEnv* env);
 
 }  // namespace banners
 
 #endif  // CHROME_BROWSER_ANDROID_BANNERS_APP_BANNER_MANAGER_H_