[Android WebView] Add an API to control favicon loading.

android_webview/browser/icon_helper.h

 // Copyright (c) 2013 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 ANDROID_WEBVIEW_BROWSER_ICON_HELPER_H_
 #define ANDROID_WEBVIEW_BROWSER_ICON_HELPER_H_
 
 #include <string>
 #include "content/public/browser/web_contents_observer.h"
 #include "url/gurl.h"
 
 class SkBitmap;
 
 namespace content {
 struct FaviconURL;
 }
 
 namespace gfx {
 class Size;
 }
 
 namespace android_webview {
 
 // A helper that observes favicon changes for Webview.
 class IconHelper : public content::WebContentsObserver {
  public:
   class Listener {
    public:
+    virtual bool ShouldDownloadFavicon(const GURL& icon_url) = 0;
     virtual void OnReceivedIcon(const GURL& icon_url,
                                 const SkBitmap& bitmap) = 0;
     virtual void OnReceivedTouchIconUrl(const std::string& url,
                                         const bool precomposed) = 0;
    protected:
     virtual ~Listener() {}
   };
 
   explicit IconHelper(content::WebContents* web_contents);
   virtual ~IconHelper();
@@ skipping 13 matching lines @@
 
  private:
   Listener* listener_;
 
   DISALLOW_COPY_AND_ASSIGN(IconHelper);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_ICON_HELPER_H_