Add a class to parse answer json.

components/omnibox/autocomplete_match.h

Index: components/omnibox/autocomplete_match.h
diff --git a/components/omnibox/autocomplete_match.h b/components/omnibox/autocomplete_match.h
index cb1f6e4258f80a00e0c0b861ca15e0ecfdeef475..c4c854d16ec87f3c8f893ae2f908d796dc031422 100644
--- a/components/omnibox/autocomplete_match.h
+++ b/components/omnibox/autocomplete_match.h
@@ -16,6 +16,7 @@
 #include "url/gurl.h"
 
 class AutocompleteProvider;
+class SuggestionAnswer;
 class TemplateURL;
 class TemplateURLService;
 
@@ -320,6 +321,7 @@ struct AutocompleteMatch {
   // A rich-format version of the display for the dropdown.
   base::string16 answer_contents;

[groby-ooo-7-16, 2014/10/21 00:35:54]

Since we make answer optional, I think we should put contents/type into
SuggestionAnswer as well. (Also, we can probably remove contents as soon as we
can move SuggestionAnswer to the Java side)

[Justin Donnelly, 2014/10/21 21:43:54]

Agreed.  Once I update Clank to use the new type, I'll remove the contents and
type fields.  (I already had a TODO in SuggestResult and I've added one here in
AutocompleteMatch.)  I already put type into answer.  It's not clear that we'll
actually need a string contents field, but I can add it later if necessary.

   base::string16 answer_type;
+  scoped_ptr<SuggestionAnswer> answer;
 
   // The transition type to use when the user opens this match.  By default
   // this is TYPED.  Providers whose matches do not look like URLs should set