chromeos: Stop calling ProfileManager::GetDefaultProfile() from extension event dispatch functions

chrome/browser/chromeos/power/brightness_observer.h

 // Copyright (c) 2012 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_CHROMEOS_POWER_BRIGHTNESS_OBSERVER_H_
 #define CHROME_BROWSER_CHROMEOS_POWER_BRIGHTNESS_OBSERVER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "chromeos/dbus/power_manager_client.h"
 
+class Profile;
+
 namespace chromeos {
 
 // This observer listens for changes to the screen brightness and notifies
 // extensions and ash::PowerButtonController about them.
 class BrightnessObserver : public PowerManagerClient::Observer {
  public:
   // This class registers/unregisters itself as an observer in ctor/dtor.
-  BrightnessObserver();
+  explicit BrightnessObserver(Profile* profile);
   virtual ~BrightnessObserver();
 
  private:
   // PowerManagerClient::Observer implementation.
   virtual void BrightnessChanged(int level, bool user_initiated) OVERRIDE;
 
+  Profile* profile_;
+
   DISALLOW_COPY_AND_ASSIGN(BrightnessObserver);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_POWER_BRIGHTNESS_OBSERVER_H_