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

chrome/browser/banners/app_banner_data_fetcher.h

Index: chrome/browser/banners/app_banner_data_fetcher.h
diff --git a/chrome/browser/banners/app_banner_data_fetcher.h b/chrome/browser/banners/app_banner_data_fetcher.h
index 6327453104c4ede3b678af17efe235115dd88da2..bb9a6922b637d5c83d61c1a47469ccbaadb09080 100644
--- a/chrome/browser/banners/app_banner_data_fetcher.h
+++ b/chrome/browser/banners/app_banner_data_fetcher.h
@@ -138,9 +138,14 @@ class AppBannerDataFetcher
   // 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_;