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

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

 // 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.
 
 #include "chrome/browser/chromeos/chrome_browser_main_chromeos.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/shell.h"
@@ skipping 439 matching lines @@
   // Tests should be able to tune login manager before showing it.
   // Thus only show login manager in normal (non-testing) mode.
   if (!parameters().ui_task)
     OptionallyRunChromeOSLoginManager(parsed_command_line(), profile());
 
   // These observers must be initialized after the profile because
   // they use the profile to dispatch extension events.
   //
   // Initialize the brightness observer so that we'll display an onscreen
   // indication of brightness changes during login.
-  brightness_observer_.reset(new chromeos::BrightnessObserver());
+  brightness_observer_.reset(new chromeos::BrightnessObserver(profile()));

[satorux1, 2012/09/13 00:42:56]

Please write some comment about why these observers need to take profile() and
cache the pointer

[hashimoto, 2012/09/13 01:01:40]

There is already a comment "they use the profile to dispatch extension events"
above.
And I don't think we should add some comment about why we are not using
GetDefaultProfile() since ProfileManager::GetDefaultProfile() is marked as
DEPRECATED in profile_manager.h (even though they allow Chrome OS code to use
it).

Thoughts?

[satorux1, 2012/09/13 01:13:46]

I thought it'd be nice to explain why these observers need to cache the pointer
to the Profile used at this moment (Profile for login), as it's solving a subtle
problem.

   output_observer_.reset(new chromeos::OutputObserver());
-  resume_observer_.reset(new chromeos::ResumeObserver());
-  screen_lock_observer_.reset(new chromeos::ScreenLockObserver());
+  resume_observer_.reset(new chromeos::ResumeObserver(profile()));
+  screen_lock_observer_.reset(new chromeos::ScreenLockObserver(profile()));
   if (chromeos::KioskModeSettings::Get()->IsKioskModeEnabled())
     power_state_override_.reset(new chromeos::PowerStateOverride());
 
   media_device_notifications_ = new chromeos::MediaDeviceNotifications();
 
   ChromeBrowserMainPartsLinux::PostProfileInit();
 }
 
 void ChromeBrowserMainPartsChromeos::PreBrowserStart() {
   // -- This used to be in ChromeBrowserMainParts::PreMainMessageLoopRun()
@@ skipping 136 matching lines @@
       LOG(WARNING) << "low_mem: Part of '100MB' experiment";
       chromeos::LowMemoryObserver::SetLowMemoryMargin(100);
     } else if (trial->group() == margin_200mb) {
       LOG(WARNING) << "low_mem: Part of '200MB' experiment";
       chromeos::LowMemoryObserver::SetLowMemoryMargin(200);
     } else {
       LOG(WARNING) << "low_mem: Part of 'default' experiment";
     }
   }
 }