Qualify RuntimeEnabledFeatures.h and remove unnecessary include dir.

Source/modules/encryptedmedia/HTMLMediaElementEncryptedMedia.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/encryptedmedia/HTMLMediaElementEncryptedMedia.h"
 
-#include "RuntimeEnabledFeatures.h"
 #include "bindings/v8/ExceptionState.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/MediaKeyError.h"
 #include "core/html/MediaKeyEvent.h"
 #include "modules/encryptedmedia/MediaKeyNeededEvent.h"
 #include "modules/encryptedmedia/MediaKeys.h"
 #include "platform/Logging.h"
+#include "platform/RuntimeEnabledFeatures.h"
 
 namespace WebCore {
 
 static void throwExceptionIfMediaKeyExceptionOccurred(const String& keySystem, const String& sessionId, blink::WebMediaPlayer::MediaKeyException exception, ExceptionState& exceptionState)
 {
     switch (exception) {
     case blink::WebMediaPlayer::MediaKeyExceptionNoError:
         return;
     case blink::WebMediaPlayer::MediaKeyExceptionInvalidPlayerState:
         exceptionState.throwDOMException(InvalidStateError, "The player is in an invalid state.");
@@ skipping 322 matching lines @@
     return thisElement.contentDecryptionModule();
 }
 
 void HTMLMediaElementEncryptedMedia::trace(Visitor* visitor)
 {
     visitor->trace(m_mediaKeys);
     WillBeHeapSupplement<HTMLMediaElement>::trace(visitor);
 }
 
 } // namespace WebCore