Add other variations (with ids) for NTPSnippets to chrome://flags

components/variations/variations_http_header_provider.h

Index: components/variations/variations_http_header_provider.h
diff --git a/components/variations/variations_http_header_provider.h b/components/variations/variations_http_header_provider.h
index b92daca3a549a66626793d67aeca3a0a2012ed33..f63b3e150de16f493d5c91ee726450bc64d79aa1 100644
--- a/components/variations/variations_http_header_provider.h
+++ b/components/variations/variations_http_header_provider.h
@@ -41,12 +41,19 @@ class VariationsHttpHeaderProvider : public base::FieldTrialList::Observer,
   // a leading and trailing space, e.g. " 123 234 345 ".
   std::string GetVariationsString();
 
+  // Forces the list of |variation_ids| (possible extended by a comma separated
+  // list of |command_line_variation_ids| passed in a command line flag). This

[Alexei Svitkine (slow), 2016/07/27 15:04:18]

Can you make this a little bit more explicit about it modifying
|variations_ids|.

e.g. "possible extended" -> "which will be extended by the comma-separated
|command_line_variation_ids|"

[jkrcal, 2016/07/27 17:12:44]

Done.

+  // is a wrapper function around SetDefaultVariationIds.
+  bool ForceVariationIds(
+      std::vector<std::string>* variation_ids,

[Alexei Svitkine (slow), 2016/07/27 15:04:18]

Nit: Non-const params should be last.

[jkrcal, 2016/07/27 17:12:44]

Done.

+      const std::string& command_line_variation_ids);
+
   // Sets *additional* variation ids and trigger variation ids to be encoded in
-  // the X-Client-Data request header.  This is intended for development use to
-  // force a server side experiment id.  |variation_ids| should be a
-  // comma-separated string of numeric experiment ids.  If an id is prefixed
-  // with "t" it will be treated as a trigger experiment id.
-  bool SetDefaultVariationIds(const std::string& variation_ids);
+  // the X-Client-Data request header. This is intended for development use to
+  // force a server side experiment id. |variation_ids| should be a list of
+  // strings of numeric experiment ids. If an id is prefixed with "t" it will
+  // be treated as a trigger experiment id.
+  bool SetDefaultVariationIds(const std::vector<std::string>& variation_ids);
 
   // Resets any cached state for tests.
   void ResetForTesting();