Getting rid of GetDefaultProfile & fixing multi user issues with accessibility

chrome/browser/chromeos/accessibility/magnification_manager.cc

Index: chrome/browser/chromeos/accessibility/magnification_manager.cc
diff --git a/chrome/browser/chromeos/accessibility/magnification_manager.cc b/chrome/browser/chromeos/accessibility/magnification_manager.cc
index 30519080d722aa042dda0d6582f0f27865858209..15bfea332e39e09d517c66974d228ee02970d479 100644
--- a/chrome/browser/chromeos/accessibility/magnification_manager.cc
+++ b/chrome/browser/chromeos/accessibility/magnification_manager.cc
@@ -8,6 +8,7 @@
 
 #include "ash/magnifier/magnification_controller.h"
 #include "ash/magnifier/partial_magnification_controller.h"
+#include "ash/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "ash/system/tray/system_tray_notifier.h"
@@ -35,7 +36,8 @@ static MagnificationManager* g_magnification_manager = NULL;
 }
 
 class MagnificationManagerImpl : public MagnificationManager,
-                                 public content::NotificationObserver {
+                                 public content::NotificationObserver,
+                                 public ash::SessionStateObserver {
  public:
   MagnificationManagerImpl()
       : first_time_update_(true),
@@ -44,7 +46,8 @@ class MagnificationManagerImpl : public MagnificationManager,
         magnifier_type_pref_handler_(prefs::kScreenMagnifierType),
         magnifier_scale_pref_handler_(prefs::kScreenMagnifierScale),
         type_(ash::kDefaultMagnifierType),
-        enabled_(false) {
+        enabled_(false),
+        session_state_observer_installed_(false) {
     registrar_.Add(this,
                    chrome::NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE,
                    content::NotificationService::AllSources());
@@ -58,6 +61,9 @@ class MagnificationManagerImpl : public MagnificationManager,
 
   virtual ~MagnificationManagerImpl() {
     CHECK(this == g_magnification_manager);
+    if (session_state_observer_installed_)
+      ash::Shell::GetInstance()->session_state_delegate()->
+          RemoveSessionStateObserver(this);
   }
 
   // MagnificationManager implimentation:
@@ -105,6 +111,11 @@ class MagnificationManagerImpl : public MagnificationManager,
     SetProfile(profile);
   }
 
+  // SessionStateObserver overrides:
+  virtual void ActiveUserChanged(const std::string& user_id) OVERRIDE {
+    SetProfile(ProfileManager::GetActiveUserProfile());
+  }
+
  private:
   void SetProfile(Profile* profile) {
     pref_change_registrar_.reset();
@@ -209,6 +220,13 @@ class MagnificationManagerImpl : public MagnificationManager,
       case chrome::NOTIFICATION_SESSION_STARTED:
         // Update |profile_| when entering a session.
         SetProfile(ProfileManager::GetDefaultProfile());
+
+        // Add a session state observer to be able to monitor session changes.
+        if (!session_state_observer_installed_ && ash::Shell::HasInstance()) {
+          session_state_observer_installed_ = true;
+          ash::Shell::GetInstance()->session_state_delegate()->
+              AddSessionStateObserver(this);
+        }
         break;
       case chrome::NOTIFICATION_PROFILE_DESTROYED: {
         // Update |profile_| when exiting a session or shutting down.
@@ -229,6 +247,10 @@ class MagnificationManagerImpl : public MagnificationManager,
 
   ash::MagnifierType type_;
   bool enabled_;
+
+  // True when the session state observer was installed.
+  bool session_state_observer_installed_;
+
   content::NotificationRegistrar registrar_;
   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;