From ff1dcc28200637586bf03d990800ede438cd766e Mon Sep 17 00:00:00 2001
From: Joey Parrish <joeyparrish@google.com>
Date: Wed, 14 Oct 2015 11:22:42 -0700
Subject: [PATCH] Refine MediaKeys polyfill error type

Inspired by code in pull #176

Change-Id: I2e29310c8a3583ed208d7bd1ae2e747a92ddf480
---
 lib/polyfill/patchedmediakeys_v01b.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/polyfill/patchedmediakeys_v01b.js b/lib/polyfill/patchedmediakeys_v01b.js
index f37b7b9aa1..71c1daa0b6 100644
--- a/lib/polyfill/patchedmediakeys_v01b.js
+++ b/lib/polyfill/patchedmediakeys_v01b.js
@@ -247,7 +247,14 @@ shaka.polyfill.PatchedMediaKeys.v01b.MediaKeySystemAccess =
     }
   }  // for each cfg in supportedConfigurations
 
-  throw Error('None of the requested configurations were supported.');
+  var message = 'Unsupported keySystem';
+  if (keySystem == 'org.w3.clearkey' || keySystem == 'com.widevine.alpha') {
+    message = 'None of the requested configurations were supported.';
+  }
+  var unsupportedError = new Error(message);
+  unsupportedError.name = 'NotSupportedError';
+  unsupportedError.code = DOMException.NOT_SUPPORTED_ERR;
+  throw unsupportedError;
 };