[Android] Allow setting recently visited search engines as default search engine

components/search_engines/template_url_service.h

Index: components/search_engines/template_url_service.h
diff --git a/components/search_engines/template_url_service.h b/components/search_engines/template_url_service.h
index 801ca6364295522dc093aff93e476256ab2f7a01..4a8a5af3f6d10e7d484ffa77b6b7216b78a262f8 100644
--- a/components/search_engines/template_url_service.h
+++ b/components/search_engines/template_url_service.h
@@ -133,11 +133,14 @@ class TemplateURLService : public WebDataServiceConsumer,
                                   const GURL& url,
                                   TemplateURL** template_url_to_replace);
 
-  // Returns whether |template_url| should be shown in the list of engines
-  // most likely to be selected as a default engine. This is meant to highlight
-  // the current default, as well as the other most likely choices of default
-  // engine, separately from a full list of all TemplateURLs (which might be
-  // very long).
+  // Returns whether the engine is a "pre-existing" engine, either from the
+  // prepopulate list or created by policy.
+  bool IsPrepopulatedOrCreatedByPolicy(const TemplateURL* template_url);
+
+  // Returns whether |template_url| is the current default or return true for
+  // IsPrepopulatedOrCreatedByPolicy(). This is meant to highlight the current,
+  // default, as well as the other most likely choices of default engine,
+  // separately from a full list of all TemplateURLs (which might be very long).

[Peter Kasting, 2016/11/30 07:36:49]

Nit: I still would revert this comment to the original one on this function,
which seems clearer.

   bool ShowInDefaultList(const TemplateURL* template_url);
 
   // Adds to |matches| all TemplateURLs whose keywords begin with |prefix|,