Save favicon during reading list distillation

ios/web/public/favicon_url.h

Index: ios/web/public/favicon_url.h
diff --git a/ios/web/public/favicon_url.h b/ios/web/public/favicon_url.h
index 765c292e07a16eff11935189042c3952aee79fc0..29ec6350a680c01687f8452ae9a3e0188035abc6 100644
--- a/ios/web/public/favicon_url.h
+++ b/ios/web/public/favicon_url.h
@@ -10,6 +10,10 @@
 #include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
 
+namespace base {
+class ListValue;
+}
+
 namespace web {
 
 // The favicon url from the render.
@@ -40,6 +44,11 @@ struct FaviconURL {
   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_