Do the codec string parsing for MSE in media, instead of Blink

Source/modules/mediasource/MediaSource.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 123 matching lines @@
 
     // 4. If the readyState attribute is not in the "open" state then throw an
     // InvalidStateError exception and abort these steps.
     if (!isOpen()) {
         exceptionState.throwDOMException(InvalidStateError, "The MediaSource's readyState is not 'open'.");
         return 0;
     }
 
     // 5. Create a new SourceBuffer object and associated resources.
     ContentType contentType(type);
-    Vector<String> codecs = contentType.codecs();
+    String codecs = contentType.parameter("codecs");
     OwnPtr<WebSourceBuffer> webSourceBuffer = createWebSourceBuffer(contentType.type(), codecs, exceptionState);
 
     if (!webSourceBuffer) {
         ASSERT(exceptionState.code() == NotSupportedError || exceptionState.code() == QuotaExceededError);
         // 2. If type contains a MIME type that is not supported ..., then throw a NotSupportedError exception and abort these steps.
         // 3. If the user agent can't handle any more SourceBuffer objects then throw a QuotaExceededError exception and abort these steps
         return 0;
     }
 
     SourceBuffer* buffer = SourceBuffer::create(webSourceBuffer.release(), this, m_asyncEventQueue.get());
@@ skipping 399 matching lines @@
 }
 
 void MediaSource::stop()
 {
     m_asyncEventQueue->close();
     if (!isClosed())
         setReadyState(closedKeyword());
     m_webMediaSource.clear();
 }
 
-PassOwnPtr<WebSourceBuffer> MediaSource::createWebSourceBuffer(const String& type, const Vector<String>& codecs, ExceptionState& exceptionState)
+PassOwnPtr<WebSourceBuffer> MediaSource::createWebSourceBuffer(const String& type, const String& codecs, ExceptionState& exceptionState)
 {
     WebSourceBuffer* webSourceBuffer = 0;
 
     switch (m_webMediaSource->addSourceBuffer(type, codecs, &webSourceBuffer)) {
     case WebMediaSource::AddStatusOk:
         return adoptPtr(webSourceBuffer);
     case WebMediaSource::AddStatusNotSupported:
         ASSERT(!webSourceBuffer);
         // 2.2 https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#widl-MediaSource-addSourceBuffer-SourceBuffer-DOMString-type
         // Step 2: If type contains a MIME type ... that is not supported with the types
@@ skipping 23 matching lines @@
 
     m_asyncEventQueue->enqueueEvent(event.release());
 }
 
 URLRegistry& MediaSource::registry() const
 {
     return MediaSourceRegistry::registry();
 }
 
 } // namespace blink