Add W3C encrypted-media tests

third_party/WebKit/LayoutTests/imported/wpt/encrypted-media/util/clearkey-messagehandler.js

+// Expect utf8decoder and utf8decoder to be TextEncoder('utf-8') and TextDecoder('utf-8') respectively
+
+function MessageHandler( keysystem, content ) {
+    this._keysystem = keysystem;
+    this._content = content;
+    this.messagehandler = MessageHandler.prototype.messagehandler.bind( this );
+    this.servercertificate = undefined;
+}
+
+MessageHandler.prototype.messagehandler = function messagehandler( messageType, message )
+{
+    if ( messageType === 'license-request' )
+    {
+        var request = fromUtf8( message );
+
+        var keys = request.kids.map( function( kid ) {
+
+            var key;
+            for( var i=0; i < this._content.keys.length; ++i )
+            {
+                if ( base64urlEncode( this._content.keys[ i ].kid ) === kid )
+                {
+                    key = base64urlEncode( this._content.keys[ i ].key );
+                    break;
+                }
+            }
+
+            return { kty: 'oct', kid: kid, k: key };
+
+        }.bind( this ) );
+
+        return Promise.resolve( toUtf8( { keys: keys } ) );
+    }
+    else if ( messageType === 'license-release' )
+    {
+        var release = fromUtf8( message );
+
+        // TODO: Check the license release message here
+
+        return Promise.resolve( toUtf8( { kids: release.kids } ) );
+    }
+
+    throw new TypeError( 'Unsupported message type for ClearKey' );
+};
+
+MessageHandler.prototype.createJWKSet = function createJWKSet(keyId, key) {
+    var jwkSet = '{"keys":[';
+    for (var i = 0; i < arguments.length; i++) {
+        if (i != 0)
+            jwkSet += ',';
+        jwkSet += arguments[i];
+    }
+    jwkSet += ']}';
+    return jwkSet;
+};
+
+MessageHandler.prototype.createJWK = function createJWK(keyId, key) {
+    var jwk = '{"kty":"oct","alg":"A128KW","kid":"';
+    jwk += base64urlEncode(keyId);
+    jwk += '","k":"';
+    jwk += base64urlEncode(key);
+    jwk += '"}';
+    return jwk;
+};