Apply TypeChecking to MediaSource IDLs

Source/modules/mediasource/MediaSourceBase.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 211 matching lines @@
 {
     DEFINE_STATIC_LOCAL(const AtomicString, network, ("network", AtomicString::ConstructFromLiteral));
     DEFINE_STATIC_LOCAL(const AtomicString, decode, ("decode", AtomicString::ConstructFromLiteral));
 
     if (error == network) {
         endOfStreamInternal(blink::WebMediaSource::EndOfStreamStatusNetworkError, exceptionState);
     } else if (error == decode) {
         endOfStreamInternal(blink::WebMediaSource::EndOfStreamStatusDecodeError, exceptionState);
     } else {
         ASSERT_NOT_REACHED(); // IDL enforcement should prevent this case.
-        exceptionState.throwTypeError("parameter 1 is not a valid enum value.");
     }
 }
 
 void MediaSourceBase::endOfStream(ExceptionState& exceptionState)
 {
     endOfStreamInternal(blink::WebMediaSource::EndOfStreamStatusNoError, exceptionState);
 }
 
 void MediaSourceBase::endOfStreamInternal(const blink::WebMediaSource::EndOfStreamStatus eosStatus, ExceptionState& exceptionState)
 {
@@ skipping 113 matching lines @@
 {
     return ActiveDOMObject::executionContext();
 }
 
 URLRegistry& MediaSourceBase::registry() const
 {
     return MediaSourceRegistry::registry();
 }
 
 }