Move ZoomObserver, ZoomController and ZoomEventManager to components/.

extensions/browser/extension_zoom_request_client.h

+// Copyright 2014 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 EXTENSIONS_BROWSER_EXTENSION_ZOOM_REQUEST_CLIENT_H_
+#define EXTENSIONS_BROWSER_EXTENSION_ZOOM_REQUEST_CLIENT_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "components/ui/zoom/zoom_controller.h"
+#include "extensions/common/extension.h"
+
+namespace extensions {
+
+class Extension;
+
+class ExtensionZoomRequestClient : public components::ZoomRequestClient {

[James Cook, 2014/12/04 17:17:16]

nit: Class comment explaining why this must exist and/or what it does.

[wjmaclean, 2014/12/04 18:27:17]

Done.

+ public:
+  explicit ExtensionZoomRequestClient(scoped_refptr<const Extension> extension);
+
+  const Extension* extension() const { return extension_.get(); }
+
+ private:
+  virtual ~ExtensionZoomRequestClient();

[James Cook, 2014/12/04 17:17:16]

nit: no virtual, "override" instead

[wjmaclean, 2014/12/04 18:27:17]

Done.

Interesting, was unaware of the 'override' use with destructors.

+  scoped_refptr<const Extension> extension_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionZoomRequestClient);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_EXTENSION_ZOOM_REQUEST_CLIENT_H_