Model each Dart library as its own ScriptState when devtools are enabled.

Source/bindings/dart/DartInjectedScriptHost.h

 // Copyright 2013, Google Inc.
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 //
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 // 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
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
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 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
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 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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-#include "config.h"
-#include "DartWorkerCrypto.h"
+#ifndef DartInjectedScriptHost_h
+#define DartInjectedScriptHost_h
+
+#include <v8.h>
 
 namespace WebCore {
 
-namespace DartWorkerCryptoInternal {
-
-void getRandomValuesCallback(Dart_NativeArguments)
-{
-    // FIXME: proper implementation.
-    DART_UNIMPLEMENTED();
-}
+class DartInjectedScriptHost {
+public:
+    static v8::Handle<v8::Value> evaluateIfDartContext(v8::Handle<v8::Object> v8InjectedScriptHost, v8::Handle<v8::String> expression);
+};
 
 }
 
-}
+#endif // DartInjectedScriptHost_h