Remove WebContents::HasManifest.

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index 8cf454ca8493b7a54eae0f194a76fc1de22e106f..36996f00cdc50c5c21055e96450d1200cdca1bf1 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -691,19 +691,15 @@ class WebContents : public PageNavigator,
   // Returns true if audio has recently been audible from the WebContents.
   virtual bool WasRecentlyAudible() = 0;
 
+  // The callback invoked when the renderer responds to a request for the main
+  // frame document's manifest. The url will be empty if the document specifies
+  // no manifest, and the manifest will be empty if any other failures occurred.
   typedef base::Callback<void(const GURL&, const Manifest&)>
       GetManifestCallback;
 
   // Requests the manifest URL and the Manifest of the main frame's document.
   virtual void GetManifest(const GetManifestCallback& callback) = 0;
 
-  typedef base::Callback<void(bool)> HasManifestCallback;
-
-  // Returns true if the main frame has a <link> to a web manifest, otherwise
-  // false. This method does not guarantee that the manifest exists at the
-  // specified location or is valid.
-  virtual void HasManifest(const HasManifestCallback& callback) = 0;
-
   // Requests the renderer to exit fullscreen.
   // |will_cause_resize| indicates whether the fullscreen change causes a
   // view resize. e.g. This will be false when going from tab fullscreen to