Add support for variations controlled overriding UI strings to the variations service.

components/variations/proto/study.proto

Index: components/variations/proto/study.proto
diff --git a/components/variations/proto/study.proto b/components/variations/proto/study.proto
index e58b8f9092aa78dc3f67347930048557cb9b6c52..18abcd5c7952e4f167eb74ba00676ffaa33a0276 100644
--- a/components/variations/proto/study.proto
+++ b/components/variations/proto/study.proto
@@ -43,7 +43,7 @@ message Study {
 
   // An experiment within the study.
   //
-  // Next tag: 9
+  // Next tag: 10
   message Experiment {
     // A named parameter value for this experiment.
     //
@@ -107,6 +107,16 @@ message Study {
       KILL_CRITICAL = 3;
     }
     optional Type type = 7 [default = NORMAL];
+
+    // A UI string to override, and the new value to use. |name_hash| is the
+    // hash of the resource name to be overridden.
+    message OverrideUIString {
+      // The first 32 bits of the MD5 hash digest of the resource name to
+      // override.
+      optional fixed32 name_hash = 1;  // e.g. Hash("IDS_BOOKMARK_BAR_UNDO")

[Alexei Svitkine (slow), 2014/07/15 16:44:52]

Nit: Move this line comment to be at the end of the comment above this member.

[jwd, 2014/07/16 21:33:05]

Done.

+      optional string value = 2;  // e.g. "Undo"

[Alexei Svitkine (slow), 2014/07/15 16:44:52]

Nit: Put comment above the field instead with a short description sentence
first, e.g.

"The override text, e.g. "Undo."

[jwd, 2014/07/16 21:33:05]

Done.

+    }
+    repeated OverrideUIString override_ui_string = 9;
   }
 
   // List of experiments in this study. This list should include the default /