Log messages regarding why app banners aren't displayed to the console

chrome/browser/banners/app_banner_data_fetcher.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_DATA_FETCHER_H_
 #define CHROME_BROWSER_BANNERS_APP_BANNER_DATA_FETCHER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 120 matching lines @@
   // Shows a banner for the app, if the given |icon| is valid.
   virtual void ShowBanner(const SkBitmap* icon);
 
   // Record that the banner could be shown at this point, if the triggering
   // heuristic allowed.
   void RecordCouldShowBanner();
 
   // Returns whether the banner should be shown.
   bool CheckIfShouldShowBanner();
 
+  // Returns whether the fetcher is active and web contents have not been
+  // closed.
+  bool CheckFetcherIsStillAlive(content::WebContents* web_contents);
+
   // Returns whether the given Manifest is following the requirements to show
   // a web app banner.
-  static bool IsManifestValidForWebApp(const content::Manifest& manifest);
+  static bool IsManifestValidForWebApp(const content::Manifest& manifest,
+                                       content::WebContents* web_contents);
 
   const int ideal_icon_size_;
   const base::WeakPtr<Delegate> weak_delegate_;
   ObserverList<Observer> observer_list_;
   bool is_active_;
   int event_request_id_;
   scoped_ptr<chrome::BitmapFetcher> bitmap_fetcher_;
   scoped_ptr<SkBitmap> app_icon_;
 
   GURL validated_url_;
   base::string16 app_title_;
   content::Manifest web_app_data_;
 
   friend class AppBannerDataFetcherUnitTest;
   friend class base::RefCounted<AppBannerDataFetcher>;
   DISALLOW_COPY_AND_ASSIGN(AppBannerDataFetcher);
 };
 
 }  // namespace banners
 
 #endif  // CHROME_BROWSER_BANNERS_APP_BANNER_DATA_FETCHER_H_