ScriptContextSetTest should close the main frame before finishing the test

extensions/renderer/scoped_web_frame.h

+// 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/WebFrame.h"
+#include "third_party/WebKit/public/web/WebHeap.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebView.h"
+
+namespace extensions {
+
+class ScopedWebFrame {

[not at google - send to devlin, 2015/06/25 15:20:16]

This should be split into a .h and a .cc file. The code I wrote was optimised
for brevity.

Also when you do please add an overall class comment.

[haraken, 2015/06/26 00:35:34]

Done.

+public:
+  ScopedWebFrame() : view_(nullptr), frame_(nullptr) {
+    view_ = blink::WebView::create(nullptr);
+    frame_ = blink::WebLocalFrame::create(
+        blink::WebTreeScopeType::Document, nullptr);
+    view_->setMainFrame(frame_);
+  }
+
+  ~ScopedWebFrame() {
+    view_->close();
+    frame_->close();
+    blink::WebHeap::collectAllGarbageForTesting();
+  }
+
+  blink::WebLocalFrame* frame() { return frame_; }
+
+private:
+  blink::WebView* view_;

[not at google - send to devlin, 2015/06/25 15:20:16]

Is there a comment here you could make about the lifetime? I never understood
why you're not supposed to delete these, since you created them.

If you don't know that's fine. Neither do I. In that case, I'd just vaguely
mention "These manage their own lifetime" so that anybody reading the code
doesn't put them in a scoped_ptr and cause a bug. Which I did once :-)

[haraken, 2015/06/26 00:35:34]

Added a comment. It's not nice that the content layer sometimes holds a raw
pointer into Blink. It's causing a lot of use-after-frees (this is one of the
biggest causes of use-after-frees detected by Oilpan)...

+  blink::WebLocalFrame* frame_;

[not at google - send to devlin, 2015/06/25 15:20:16]

Also DISALLOW_COPY_AND_ASSIGN.

[haraken, 2015/06/26 00:35:34]

Done.

+};
+
+}  // namespace extensions
+
+#endif  // SCOPED_WEB_FRAME_H_