Add window.crypto.subtle behind a runtime feature flag ("Crypto")

Source/modules/crypto/Crypto.h

 /*
  * Copyright (C) 2011 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 12 matching lines @@
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef Crypto_h
 #define Crypto_h
 
 #include "bindings/v8/ScriptWrappable.h"
+#include "modules/crypto/SubtleCrypto.h"
 #include "wtf/Forward.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
 typedef int ExceptionCode;
 
 class Crypto : public ScriptWrappable, public RefCounted<Crypto> {
 public:
     static PassRefPtr<Crypto> create() { return adoptRef(new Crypto()); }
 
     void getRandomValues(ArrayBufferView*, ExceptionCode&);
 
+    SubtleCrypto* subtle();
+
 private:
     Crypto();
+
+    RefPtr<SubtleCrypto> m_subtleCrypto;
 };
 
 }
 
 #endif