EME: Fix the CDM File IO test when run using unprefixed EME.

media/test/data/eme_player_js/utils.js

Index: media/test/data/eme_player_js/utils.js
diff --git a/media/test/data/eme_player_js/utils.js b/media/test/data/eme_player_js/utils.js
index 00e23ac44ca28be592c046127a40d2b1507f2e93..41a4d45c322855e4a3dd3e57e660582f4ddd1796 100644
--- a/media/test/data/eme_player_js/utils.js
+++ b/media/test/data/eme_player_js/utils.js
@@ -175,7 +175,7 @@ Utils.getHexString = function(uintArray) {
 };
 
 Utils.hasPrefix = function(msg, prefix) {
-  var message = String.fromCharCode.apply(null, msg);
+  var message = String.fromCharCode.apply(null, Utils.convertToUint8Array(msg));

[ddorwin, 2016/02/20 00:09:10]

Since there is no way to assert that a Uint8Array was passed in, always do the
conversion.

   return message.substring(0, prefix.length) == prefix;
 };
 
@@ -199,8 +199,7 @@ Utils.isRenewalMessage = function(message) {
 // For the prefixed API renewal messages are determined by looking at the
 // message and finding a known string.
 Utils.isRenewalMessagePrefixed = function(msg) {
-  return Utils.hasPrefix(Utils.convertToUint8Array(msg),
-                         PREFIXED_EME_RENEWAL_MESSAGE_HEADER);
+  return Utils.hasPrefix(msg, PREFIXED_EME_RENEWAL_MESSAGE_HEADER);
 };
 
 Utils.resetTitleChange = function() {