Save favicon during reading list distillation

ios/web/public/favicon_url.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 IOS_WEB_PUBLIC_FAVICON_URL_
 #define IOS_WEB_PUBLIC_FAVICON_URL_
 
 #include <vector>
 
 #include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
 
+namespace base {
+class ListValue;
+}
+
 namespace web {
 
 // The favicon url from the render.
 struct FaviconURL {
   // The icon type in a page. The definition must be same as
   // favicon_base::IconType.
   enum IconType {
     INVALID_ICON = 0x0,
     FAVICON = 1 << 0,
     TOUCH_ICON = 1 << 1,
@@ skipping 10 matching lines @@
   // The url of the icon.
   GURL icon_url;
 
   // The type of the icon
   IconType icon_type;
 
   // Icon's bitmaps' size
   std::vector<gfx::Size> icon_sizes;
 };
 
+// Extract the favicons stored in |favicons| using the format: [ {"href":
+// the_url, "rel": favicon_type}, ...] and store them in |result_urls|.
+bool ExtractFaviconURL(base::ListValue* favicons,

[Eugene But (OOO till 7-30), 2016/11/30 18:51:31]

Do we need this as a part of public API? WebStateObserver already provides a way
to get favicon URLs. If ios/web does not provide necessary API then we should
look at other platforms for inspiration and use the same approach where
possible.

+                       std::vector<web::FaviconURL>& result_urls);

[kkhorimoto, 2016/11/28 23:48:26]

The style guide dictates that out-parameters should be pointers.  Passing by
reference should only be used for const references in order to avoid copying
larger objects.  Additionally, the comment here should explain what conditions
will cause this function to return false.

https://engdoc.corp.google.com/eng/doc/devguide/cpp/styleguide.shtml?cl=head#...

+
 } // namespace web
 
 #endif  // IOS_WEB_PUBLIC_FAVICON_URL_