Switch SupportsUserData uses to use unique_ptr.

chrome/browser/extensions/chrome_extension_web_contents_observer.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 CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSION_WEB_CONTENTS_OBSERVER_H_
 #define CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSION_WEB_CONTENTS_OBSERVER_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "content/public/browser/web_contents_user_data.h"
 #include "extensions/browser/extension_web_contents_observer.h"
 #include "extensions/common/stack_frame.h"
 
 namespace content {
 class RenderFrameHost;
 }
 
 namespace extensions {
 
 // An ExtensionWebContentsObserver that adds support for the extension error
 // console, reloading crashed extensions and routing extension messages between
 // renderers.
 class ChromeExtensionWebContentsObserver
     : public ExtensionWebContentsObserver,
       public content::WebContentsUserData<ChromeExtensionWebContentsObserver> {
+ public:
+  ~ChromeExtensionWebContentsObserver() override;
+
  private:
   friend class content::WebContentsUserData<ChromeExtensionWebContentsObserver>;
 
   explicit ChromeExtensionWebContentsObserver(
       content::WebContents* web_contents);
-  ~ChromeExtensionWebContentsObserver() override;
 
   // ExtensionWebContentsObserver:
   void InitializeRenderFrame(
       content::RenderFrameHost* render_frame_host) override;
 
   // content::WebContentsObserver overrides.
   void RenderViewCreated(content::RenderViewHost* render_view_host) override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
 
@@ skipping 15 matching lines @@
   // Determines which bucket of a synthetic field trial this client belongs
   // to and sets it.
   void SetExtensionIsolationTrial(content::RenderFrameHost* render_frame_host);
 
   DISALLOW_COPY_AND_ASSIGN(ChromeExtensionWebContentsObserver);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_CHROME_EXTENSION_WEB_CONTENTS_OBSERVER_H_