Protector bubble cancels itself if user changes default search engine manually.

chrome/browser/protector/protector.h

 // Copyright (c) 2011 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_PROTECTOR_PROTECTOR_H_
 #define CHROME_BROWSER_PROTECTOR_PROTECTOR_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 13 matching lines @@
 // Presents a SettingChange to user and handles possible user actions.
 // Deletes itself after a user action is taken or timeout expires.
 class Protector : public SettingsChangeGlobalErrorDelegate {
  public:
   explicit Protector(Profile* profile);
 
   // Opens a tab with specified URL in the browser window we've shown error
   // bubble for.
   void OpenTab(const GURL& url);
 
-  // Returns TemplateURLService for the profile we've shown error bubble
-  // for.
+  // Returns TemplateURLService for the profile we've shown error bubble for.
   TemplateURLService* GetTemplateURLService();
 
-  // Shows global error about the specified change. Ownership of the change
-  // is passed to the GlobalError object.
+  // Shows global error about the specified change. Owns |change|.
   void ShowChange(BaseSettingChange* change);
 
+  // Silently discards any change previously shown (without calling Discard),
+  // removes global error and deletes itself.
+  void DismissChange();
+
   // SettingsChangeGlobalErrorDelegate implementation.
   virtual void OnApplyChange() OVERRIDE;
   virtual void OnDiscardChange() OVERRIDE;
   virtual void OnDecisionTimeout() OVERRIDE;
   virtual void OnRemovedFromProfile() OVERRIDE;
 
  private:
   friend class DeleteTask<Protector>;
 
   // The object can only be allocated and destroyed on heap.
   virtual ~Protector();
 
   // Performs the initial action on settings change and shows it. This is run
   // asynchronously on UI thread because |ShowChange| may be called in the
   // middle of some operations on settings that have changed.

[whywhat, 2011/11/21 14:51:21]

You should document that object might be self-destroyed here...

[Ivan Korotkov, 2011/11/21 15:27:38]

Done.

   void InitAndShowChange(BaseSettingChange* change);
 
   // Pointer to error bubble controller. Indicates if we're showing change
-  // notification to user. Owns itself.
+  // notification to user.
   scoped_ptr<SettingsChangeGlobalError> error_;
 
+  // Setting change which we're showing.
+  scoped_ptr<BaseSettingChange> change_;
+
   // Profile which settings we are protecting.
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(Protector);
 };
 
 // Signs string value with protector's key.
 std::string SignSetting(const std::string& value);
 
 // Returns true if the signature is valid for the specified key.
 bool IsSettingValid(const std::string& value, const std::string& signature);
 
 }  // namespace protector
 
 #endif  // CHROME_BROWSER_PROTECTOR_PROTECTOR_H_