Reapply "Move isolate loading to a separate loader isolate."

Source/bindings/dart/DartController.h

Index: Source/bindings/dart/DartController.h
diff --git a/Source/bindings/dart/DartController.h b/Source/bindings/dart/DartController.h
index 504c69a36b6b048d7c81c153f4962e2a0dc51ab6..e3f2f60ac32fc6e18df2c7a93d852ab5a76b5a99 100644
--- a/Source/bindings/dart/DartController.h
+++ b/Source/bindings/dart/DartController.h
@@ -43,10 +43,12 @@ struct NPObject;
 namespace WebCore {
 
 class DartApplicationLoader;
+class DartAsyncLoader;
 class DartDOMData;
 class DartScriptState;
 class DOMWindow;
 class Frame;
+class ScriptElementProxy;
 class ScriptExecutionContext;
 class ScriptState;
 
@@ -81,6 +83,8 @@ public:
     static DartController* retrieve(Frame*);
     static DartController* retrieve(ScriptExecutionContext*);
 
+    // FIXME: Move.
+    void loadAndRunScript(const String&, PassRefPtr<DartAsyncLoader>, PassRefPtr<ScriptElementProxy>);
 private:
     static void initVMIfNeeded();
 
@@ -113,6 +117,7 @@ private:
     NPObjectMap m_npObjectMap;
 
     friend class DartScriptRunner;
+    friend class DartDomCallback;
 };
 
 }