ScriptContextSetTest should close the main frame before finishing the test

extensions/renderer/scoped_web_frame.h

Index: extensions/renderer/scoped_web_frame.h
diff --git a/extensions/renderer/scoped_web_frame.h b/extensions/renderer/scoped_web_frame.h
new file mode 100644
index 0000000000000000000000000000000000000000..7950552ad475c8ca01fe69572dc23d3b95a8e35b
--- /dev/null
+++ b/extensions/renderer/scoped_web_frame.h
@@ -0,0 +1,33 @@
+// Copyright 2015 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.
+
+#ifndef SCOPED_WEB_FRAME_H_
+#define SCOPED_WEB_FRAME_H_
+
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebView.h"
+
+namespace extensions {
+
+// ScopedWebFrame is a class to create a dummy webview and frame for testing.
+// The dymmy webview and frame will be destructed when the scope exits.
+class ScopedWebFrame {
+public:
+  ScopedWebFrame();
+  ~ScopedWebFrame();
+
+  blink::WebLocalFrame* frame() { return frame_; }
+
+private:
+  // The webview and the frame are kept alive by the ScopedWebFrame
+  // because they are not destructed unless ~ScopedWebFrame explicitly
+  // closes the webview and the frame.
+  blink::WebView* view_;
+  blink::WebLocalFrame* frame_;
+  DISALLOW_COPY_AND_ASSIGN(ScopedWebFrame);
+};
+
+}  // namespace extensions
+
+#endif  // SCOPED_WEB_FRAME_H_