Store Origin Trials public key in browser prefs

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index d47493512fa0a027b1bf6d8eb0521224773b5ccd..5d1988340fcc143c331c0ce6ddf543fcb7f48269 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -2226,4 +2226,8 @@ const char kMediaRouterFirstRunFlowAcknowledged[] =
     "media_router.firstrunflow.acknowledged";
 #endif
 
+// The base64-encoded representation of the public key to use to validate origin
+// trial token signatures.
+const char kOriginTrialPublicKey[] = "origin_trials.public_key";
+
 }  // namespace prefs