Explicitly ShutdownOnUIThread the HostContentSettingsMap when destroying the Profile.

Also, get rid of Profile dependencies while we're at it.

BUG=88037,88557

Review URL: http://codereview.chromium.org/7218073

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@92128 0039d316-1c4b-4281-b951-d872f2087c98

21 files changed, 347 insertions, 394 deletions

diff --git a/base/values.cc b/base/values.cc
index 0f30e379..adfc9a8 100644
--- a/base/values.cc
+++ b/base/values.cc
@@ -123,6 +123,10 @@ bool Value::GetAsList(ListValue** out_value) {
   return false;
 }
 
+bool Value::GetAsList(const ListValue** out_value) const {
+  return false;
+}
+
 Value* Value::DeepCopy() const {
   // This method should only be getting called for null Values--all subclasses
   // need to provide their own implementation;.
@@ -866,6 +870,12 @@ bool ListValue::GetAsList(ListValue** out_value) {
   return true;
 }
 
+bool ListValue::GetAsList(const ListValue** out_value) const {
+  if (out_value)
+    *out_value = this;
+  return true;
+}
+
 ListValue* ListValue::DeepCopy() const {
   ListValue* result = new ListValue;
 
diff --git a/base/values.h b/base/values.h
index 43894d1..a00a17c 100644
--- a/base/values.h
+++ b/base/values.h
@@ -94,6 +94,7 @@ class BASE_API Value {
   virtual bool GetAsString(std::string* out_value) const;
   virtual bool GetAsString(string16* out_value) const;
   virtual bool GetAsList(ListValue** out_value);
+  virtual bool GetAsList(const ListValue** out_value) const;
 
   // This creates a deep copy of the entire Value tree, and returns a pointer
   // to the copy.  The caller gets ownership of the copy, of course.
@@ -427,6 +428,7 @@ class BASE_API ListValue : public Value {
 
   // Overridden from Value:
   virtual bool GetAsList(ListValue** out_value);
+  virtual bool GetAsList(const ListValue** out_value) const;
   virtual ListValue* DeepCopy() const;
   virtual bool Equals(const Value* other) const;
 
diff --git a/chrome/browser/content_settings/content_settings_mock_provider.cc b/chrome/browser/content_settings/content_settings_mock_provider.cc
index d2eaaa3..78751d8 100644
--- a/chrome/browser/content_settings/content_settings_mock_provider.cc
+++ b/chrome/browser/content_settings/content_settings_mock_provider.cc
@@ -37,6 +37,9 @@ bool MockDefaultProvider::DefaultSettingIsManaged(
   return content_type == content_type_ && is_managed_;
 }
 
+void MockDefaultProvider::ShutdownOnUIThread() {
+}
+
 MockProvider::MockProvider()
     : requesting_url_pattern_(ContentSettingsPattern()),
       embedding_url_pattern_(ContentSettingsPattern()),
diff --git a/chrome/browser/content_settings/content_settings_mock_provider.h b/chrome/browser/content_settings/content_settings_mock_provider.h
index dbf006ce..3962dea 100644
--- a/chrome/browser/content_settings/content_settings_mock_provider.h
+++ b/chrome/browser/content_settings/content_settings_mock_provider.h
@@ -29,6 +29,7 @@ class MockDefaultProvider : public DefaultProviderInterface {
   virtual void UpdateDefaultSetting(ContentSettingsType content_type,
                                     ContentSetting setting);
   virtual bool DefaultSettingIsManaged(ContentSettingsType content_type) const;
+  virtual void ShutdownOnUIThread();
 
  private:
   ContentSettingsType content_type_;
@@ -76,6 +77,8 @@ class MockProvider : public ProviderInterface {
   virtual void ClearAllContentSettingsRules(
       ContentSettingsType content_type) {}
 
+  virtual void ShutdownOnUIThread() {}
+
   // Accessors
   void set_requesting_url_pattern(ContentSettingsPattern pattern) {
     requesting_url_pattern_ = pattern;
diff --git a/chrome/browser/content_settings/content_settings_notification_provider.cc b/chrome/browser/content_settings/content_settings_notification_provider.cc
index 1c71b4a..04fb00a 100644
--- a/chrome/browser/content_settings/content_settings_notification_provider.cc
+++ b/chrome/browser/content_settings/content_settings_notification_provider.cc
@@ -156,6 +156,9 @@ void NotificationProvider::ClearAllContentSettingsRules(
     ResetAllOrigins();
 }
 
+void NotificationProvider::ShutdownOnUIThread() {
+}
+
 void NotificationProvider::Observe(int type,
                                    const NotificationSource& source,
                                    const NotificationDetails& details) {
diff --git a/chrome/browser/content_settings/content_settings_notification_provider.h b/chrome/browser/content_settings/content_settings_notification_provider.h
index 69055f8..1f9caf7 100644
--- a/chrome/browser/content_settings/content_settings_notification_provider.h
+++ b/chrome/browser/content_settings/content_settings_notification_provider.h
@@ -55,6 +55,8 @@ class NotificationProvider : public ProviderInterface,
   virtual void ClearAllContentSettingsRules(
       ContentSettingsType content_type);
 
+  virtual void ShutdownOnUIThread();
+
   // NotificationObserver implementation.
   virtual void Observe(int type,
                        const NotificationSource& source,
diff --git a/chrome/browser/content_settings/content_settings_policy_provider.cc b/chrome/browser/content_settings/content_settings_policy_provider.cc
index ace204a..a13ca77 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider.cc
+++ b/chrome/browser/content_settings/content_settings_policy_provider.cc
@@ -100,17 +100,16 @@ const PrefsForManagedContentSettingsMapEntry
 
 namespace content_settings {
 
-PolicyDefaultProvider::PolicyDefaultProvider(Profile* profile)
-    : profile_(profile),
-      is_off_the_record_(profile_->IsOffTheRecord()) {
-  PrefService* prefs = profile->GetPrefs();
-
+PolicyDefaultProvider::PolicyDefaultProvider(HostContentSettingsMap* map,
+                                             PrefService* prefs)
+    : host_content_settings_map_(map),
+      prefs_(prefs) {
   // Read global defaults.
   DCHECK_EQ(arraysize(kPrefToManageType),
             static_cast<size_t>(CONTENT_SETTINGS_NUM_TYPES));
   ReadManagedDefaultSettings();
 
-  pref_change_registrar_.Init(prefs);
+  pref_change_registrar_.Init(prefs_);
   // The following preferences are only used to indicate if a
   // default-content-setting is managed and to hold the managed default-setting
   // value. If the value for any of the following perferences is set then the
@@ -123,12 +122,10 @@ PolicyDefaultProvider::PolicyDefaultProvider(Profile* profile)
   pref_change_registrar_.Add(prefs::kManagedDefaultJavaScriptSetting, this);
   pref_change_registrar_.Add(prefs::kManagedDefaultPluginsSetting, this);
   pref_change_registrar_.Add(prefs::kManagedDefaultPopupsSetting, this);
-  notification_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                              Source<Profile>(profile_));
 }
 
 PolicyDefaultProvider::~PolicyDefaultProvider() {
-  UnregisterObservers();
+  DCHECK(!prefs_);
 }
 
 ContentSetting PolicyDefaultProvider::ProvideDefaultSetting(
@@ -159,7 +156,7 @@ void PolicyDefaultProvider::Observe(int type,
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (type == chrome::NOTIFICATION_PREF_CHANGED) {
-    DCHECK_EQ(profile_->GetPrefs(), Source<PrefService>(source).ptr());
+    DCHECK_EQ(prefs_, Source<PrefService>(source).ptr());
     std::string* name = Details<std::string>(details).ptr();
     if (*name == prefs::kManagedDefaultCookiesSetting) {
       UpdateManagedDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES);
@@ -176,40 +173,33 @@ void PolicyDefaultProvider::Observe(int type,
       return;
     }
 
-    if (!is_off_the_record_) {
-      ContentSettingsDetails details(ContentSettingsPattern(),
-                                     ContentSettingsPattern(),
-                                     CONTENT_SETTINGS_TYPE_DEFAULT,
-                                     std::string());
-      NotifyObservers(details);
-    }
-  } else if (type == chrome::NOTIFICATION_PROFILE_DESTROYED) {
-    DCHECK_EQ(profile_, Source<Profile>(source).ptr());
-    UnregisterObservers();
+    ContentSettingsDetails details(ContentSettingsPattern(),
+                                   ContentSettingsPattern(),
+                                   CONTENT_SETTINGS_TYPE_DEFAULT,
+                                   std::string());
+    NotifyObservers(details);
   } else {
     NOTREACHED() << "Unexpected notification";
   }
 }
 
-void PolicyDefaultProvider::UnregisterObservers() {
+void PolicyDefaultProvider::ShutdownOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
-    return;
+  DCHECK(prefs_);
   pref_change_registrar_.RemoveAll();
-  notification_registrar_.Remove(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                                 Source<Profile>(profile_));
-  profile_ = NULL;
+  prefs_ = NULL;
+  host_content_settings_map_ = NULL;
 }
 
 
 void PolicyDefaultProvider::NotifyObservers(
     const ContentSettingsDetails& details) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (profile_ == NULL)
+  if (host_content_settings_map_ == NULL)
     return;
   NotificationService::current()->Notify(
       chrome::NOTIFICATION_CONTENT_SETTINGS_CHANGED,
-      Source<HostContentSettingsMap>(profile_->GetHostContentSettingsMap()),
+      Source<HostContentSettingsMap>(host_content_settings_map_),
       Details<const ContentSettingsDetails>(&details));
 }
 
@@ -230,12 +220,11 @@ void PolicyDefaultProvider::UpdateManagedDefaultSetting(
   // preference to manage a default-content-settings is CONTENT_SETTING_DEFAULT.
   // This indicates that no managed value is set. If a pref was set, than it
   // MUST be managed.
-  PrefService* prefs = profile_->GetPrefs();
-  DCHECK(!prefs->HasPrefPath(kPrefToManageType[type]) ||
-          prefs->IsManagedPreference(kPrefToManageType[type]));
+  DCHECK(!prefs_->HasPrefPath(kPrefToManageType[type]) ||
+          prefs_->IsManagedPreference(kPrefToManageType[type]));
   base::AutoLock auto_lock(lock_);
   managed_default_content_settings_.settings[type] = IntToContentSetting(
-      prefs->GetInteger(kPrefToManageType[type]));
+      prefs_->GetInteger(kPrefToManageType[type]));
 }
 
 // static
@@ -288,23 +277,15 @@ void PolicyProvider::RegisterUserPrefs(PrefService* prefs) {
                           PrefService::UNSYNCABLE_PREF);
 }
 
-PolicyProvider::PolicyProvider(Profile* profile,
+PolicyProvider::PolicyProvider(HostContentSettingsMap* map,
+                               PrefService* prefs,
                                DefaultProviderInterface* default_provider)
-    : profile_(profile),
+    : host_content_settings_map_(map),
+      prefs_(prefs),
       default_provider_(default_provider) {
-  Init();
-}
-
-PolicyProvider::~PolicyProvider() {
-  UnregisterObservers();
-}
-
-void PolicyProvider::Init() {
-  PrefService* prefs = profile_->GetPrefs();
-
   ReadManagedContentSettings(false);
 
-  pref_change_registrar_.Init(prefs);
+  pref_change_registrar_.Init(prefs_);
   pref_change_registrar_.Add(prefs::kManagedCookiesBlockedForUrls, this);
   pref_change_registrar_.Add(prefs::kManagedCookiesAllowedForUrls, this);
   pref_change_registrar_.Add(prefs::kManagedCookiesSessionOnlyForUrls, this);
@@ -316,29 +297,32 @@ void PolicyProvider::Init() {
   pref_change_registrar_.Add(prefs::kManagedPluginsAllowedForUrls, this);
   pref_change_registrar_.Add(prefs::kManagedPopupsBlockedForUrls, this);
   pref_change_registrar_.Add(prefs::kManagedPopupsAllowedForUrls, this);
+}
 
-  notification_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                              Source<Profile>(profile_));
+PolicyProvider::~PolicyProvider() {
+  DCHECK(!prefs_);
 }
 
 void PolicyProvider::GetContentSettingsFromPreferences(
-    PrefService* prefs,
     ContentSettingsRules* rules) {
   for (size_t i = 0; i < arraysize(kPrefsForManagedContentSettingsMap); ++i) {
     const char* pref_name = kPrefsForManagedContentSettingsMap[i].pref_name;
     // Skip unset policies.
-    if (!prefs->HasPrefPath(pref_name)) {
+    if (!prefs_->HasPrefPath(pref_name)) {
       VLOG(2) << "Skipping unset preference: " << pref_name;
       continue;
     }
 
-    const PrefService::Preference* pref = prefs->FindPreference(pref_name);
+    const PrefService::Preference* pref = prefs_->FindPreference(pref_name);
     DCHECK(pref);
     DCHECK(pref->IsManaged());
-    DCHECK_EQ(Value::TYPE_LIST, pref->GetType());
 
-    const ListValue* pattern_str_list =
-        static_cast<const ListValue*>(pref->GetValue());
+    const ListValue* pattern_str_list = NULL;
+    if (!pref->GetValue()->GetAsList(&pattern_str_list)) {
+      NOTREACHED();
+      return;
+    }
+
     for (size_t j = 0; j < pattern_str_list->GetSize(); ++j) {
       std::string original_pattern_str;
       pattern_str_list->GetString(j, &original_pattern_str);
@@ -366,8 +350,7 @@ void PolicyProvider::GetContentSettingsFromPreferences(
 
 void PolicyProvider::ReadManagedContentSettings(bool overwrite) {
   ContentSettingsRules rules;
-  PrefService* prefs = profile_->GetPrefs();
-  GetContentSettingsFromPreferences(prefs, &rules);
+  GetContentSettingsFromPreferences(&rules);
   {
     base::AutoLock auto_lock(lock_);
     if (overwrite)
@@ -443,24 +426,23 @@ void PolicyProvider::ClearAllContentSettingsRules(
     ContentSettingsType content_type) {
 }
 
-void PolicyProvider::UnregisterObservers() {
+void PolicyProvider::ShutdownOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
+  if (!prefs_)
     return;
   pref_change_registrar_.RemoveAll();
-  notification_registrar_.Remove(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                                 Source<Profile>(profile_));
-  profile_ = NULL;
+  prefs_ = NULL;
+  host_content_settings_map_ = NULL;
 }
 
 void PolicyProvider::NotifyObservers(
     const ContentSettingsDetails& details) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (profile_ == NULL)
+  if (host_content_settings_map_ == NULL)
     return;
   NotificationService::current()->Notify(
       chrome::NOTIFICATION_CONTENT_SETTINGS_CHANGED,
-      Source<HostContentSettingsMap>(profile_->GetHostContentSettingsMap()),
+      Source<HostContentSettingsMap>(host_content_settings_map_),
       Details<const ContentSettingsDetails>(&details));
 }
 
@@ -470,7 +452,7 @@ void PolicyProvider::Observe(int type,
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (type == chrome::NOTIFICATION_PREF_CHANGED) {
-    DCHECK_EQ(profile_->GetPrefs(), Source<PrefService>(source).ptr());
+    DCHECK_EQ(prefs_, Source<PrefService>(source).ptr());
     std::string* name = Details<std::string>(details).ptr();
     if (*name == prefs::kManagedCookiesAllowedForUrls ||
         *name == prefs::kManagedCookiesBlockedForUrls ||
@@ -490,9 +472,6 @@ void PolicyProvider::Observe(int type,
                                      std::string());
       NotifyObservers(details);
     }
-  } else if (type == chrome::NOTIFICATION_PROFILE_DESTROYED) {
-    DCHECK_EQ(profile_, Source<Profile>(source).ptr());
-    UnregisterObservers();
   } else {
     NOTREACHED() << "Unexpected notification";
   }
diff --git a/chrome/browser/content_settings/content_settings_policy_provider.h b/chrome/browser/content_settings/content_settings_policy_provider.h
index a992c51..394e5a7 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider.h
+++ b/chrome/browser/content_settings/content_settings_policy_provider.h
@@ -21,15 +21,15 @@
 
 class ContentSettingsDetails;
 class DictionaryValue;
+class HostContentSettingsMap;
 class PrefService;
-class Profile;
 
 namespace content_settings {
 
 class PolicyDefaultProvider : public DefaultProviderInterface,
                               public NotificationObserver {
  public:
-  explicit PolicyDefaultProvider(Profile* profile);
+  PolicyDefaultProvider(HostContentSettingsMap* map, PrefService* prefs);
   virtual ~PolicyDefaultProvider();
 
   // DefaultContentSettingsProvider implementation.
@@ -39,6 +39,8 @@ class PolicyDefaultProvider : public DefaultProviderInterface,
                                     ContentSetting setting);
   virtual bool DefaultSettingIsManaged(ContentSettingsType content_type) const;
 
+  void ShutdownOnUIThread();
+
   static void RegisterUserPrefs(PrefService* prefs);
 
   // NotificationObserver implementation.
@@ -53,8 +55,6 @@ class PolicyDefaultProvider : public DefaultProviderInterface,
   // mutex deadlock.
   void NotifyObservers(const ContentSettingsDetails& details);
 
-  void UnregisterObservers();
-
   // Reads the policy managed default settings.
   void ReadManagedDefaultSettings();
 
@@ -64,10 +64,8 @@ class PolicyDefaultProvider : public DefaultProviderInterface,
   // Copies of the pref data, so that we can read it on the IO thread.
   ContentSettings managed_default_content_settings_;
 
-  Profile* profile_;
-
-  // Whether this settings map is for an OTR session.
-  bool is_off_the_record_;
+  HostContentSettingsMap* host_content_settings_map_;
+  PrefService* prefs_;
 
   // Used around accesses to the managed_default_content_settings_ object to
   // guarantee thread safety.
@@ -83,14 +81,13 @@ class PolicyDefaultProvider : public DefaultProviderInterface,
 class PolicyProvider : public ProviderInterface,
                        public NotificationObserver {
  public:
-  explicit PolicyProvider(Profile* profile,
-                          DefaultProviderInterface* default_provider);
+  PolicyProvider(HostContentSettingsMap* map,
+                 PrefService* prefs,
+                 DefaultProviderInterface* default_provider);
   virtual ~PolicyProvider();
   static void RegisterUserPrefs(PrefService* prefs);
 
   // ProviderInterface Implementation
-  virtual void Init();
-
   virtual void SetContentSetting(
       const ContentSettingsPattern& primary_pattern,
       const ContentSettingsPattern& secondary_pattern,
@@ -112,6 +109,8 @@ class PolicyProvider : public ProviderInterface,
   virtual void ClearAllContentSettingsRules(
       ContentSettingsType content_type);
 
+  virtual void ShutdownOnUIThread();
+
   // NotificationObserver implementation.
   virtual void Observe(int type,
                        const NotificationSource& source,
@@ -128,25 +127,21 @@ class PolicyProvider : public ProviderInterface,
 
   void ReadManagedContentSettings(bool overwrite);
 
-  void GetContentSettingsFromPreferences(PrefService* prefs,
-                                         ContentSettingsRules* rules);
+  void GetContentSettingsFromPreferences(ContentSettingsRules* rules);
 
-  void ReadManagedContentSettingsTypes(
-      ContentSettingsType content_type);
+  void ReadManagedContentSettingsTypes(ContentSettingsType content_type);
 
   void NotifyObservers(const ContentSettingsDetails& details);
 
-  void UnregisterObservers();
-
   OriginIdentifierValueMap value_map_;
 
-  Profile* profile_;
+  HostContentSettingsMap* host_content_settings_map_;
+  PrefService* prefs_;
 
   // Weak, owned by HostContentSettingsMap.
   DefaultProviderInterface* default_provider_;
 
   PrefChangeRegistrar pref_change_registrar_;
-  NotificationRegistrar notification_registrar_;
 
   // Used around accesses to the content_settings_ object to guarantee
   // thread safety.
diff --git a/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc b/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc
index 8cedeca..36f321f 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_policy_provider_unittest.cc
@@ -35,8 +35,8 @@ class PolicyDefaultProviderTest : public TestingBrowserProcessTest {
 
 TEST_F(PolicyDefaultProviderTest, DefaultValues) {
   TestingProfile profile;
-  PolicyDefaultProvider provider(&profile);
   TestingPrefService* prefs = profile.GetTestingPrefService();
+  PolicyDefaultProvider provider(profile.GetHostContentSettingsMap(), prefs);
 
   // By default, policies should be off.
   ASSERT_FALSE(
@@ -54,6 +54,8 @@ TEST_F(PolicyDefaultProviderTest, DefaultValues) {
   prefs->RemoveManagedPref(prefs::kManagedDefaultCookiesSetting);
   ASSERT_FALSE(
       provider.DefaultSettingIsManaged(CONTENT_SETTINGS_TYPE_COOKIES));
+
+  provider.ShutdownOnUIThread();
 }
 
 // When a default-content-setting is set to a managed setting a
@@ -107,7 +109,7 @@ TEST_F(PolicyProviderTest, Default) {
   prefs->SetManagedPref(prefs::kManagedImagesBlockedForUrls,
                         value);
 
-  PolicyProvider provider(&profile, NULL);
+  PolicyProvider provider(profile.GetHostContentSettingsMap(), prefs, NULL);
 
   ContentSettingsPattern yt_url_pattern =
       ContentSettingsPattern::FromString("www.youtube.com");
@@ -130,6 +132,8 @@ TEST_F(PolicyProviderTest, Default) {
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
             provider.GetContentSetting(
                 youtube_url, youtube_url, CONTENT_SETTINGS_TYPE_COOKIES, ""));
+
+  provider.ShutdownOnUIThread();
 }
 
 TEST_F(PolicyProviderTest, ResourceIdentifier) {
@@ -145,7 +149,7 @@ TEST_F(PolicyProviderTest, ResourceIdentifier) {
   prefs->SetManagedPref(prefs::kManagedPluginsAllowedForUrls,
                         value);
 
-  PolicyProvider provider(&profile, NULL);
+  PolicyProvider provider(profile.GetHostContentSettingsMap(), prefs, NULL);
 
   GURL youtube_url("http://www.youtube.com");
   GURL google_url("http://mail.google.com");
@@ -173,6 +177,8 @@ TEST_F(PolicyProviderTest, ResourceIdentifier) {
                 google_url,
                 CONTENT_SETTINGS_TYPE_PLUGINS,
                 "someplugin"));
+
+  provider.ShutdownOnUIThread();
 }
 
 }  // namespace content_settings
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.cc b/chrome/browser/content_settings/content_settings_pref_provider.cc
index 56ac49b..e6c7c90 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider.cc
@@ -9,6 +9,7 @@
 #include <utility>
 #include <vector>
 
+#include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/content_settings/content_settings_details.h"
@@ -149,14 +150,15 @@ ContentSetting FixObsoleteCookiePromptMode(ContentSettingsType content_type,
 
 namespace content_settings {
 
-PrefDefaultProvider::PrefDefaultProvider(Profile* profile)
-    : profile_(profile),
-      is_incognito_(profile_->IsOffTheRecord()),
+PrefDefaultProvider::PrefDefaultProvider(HostContentSettingsMap* map,
+                                         PrefService* prefs,
+                                         bool incognito)
+    : host_content_settings_map_(map),
+      prefs_(prefs),
+      is_incognito_(incognito),
       updating_preferences_(false) {
-  initializing_ = true;
-  PrefService* prefs = profile->GetPrefs();
-
-  MigrateObsoleteNotificationPref(prefs);
+  DCHECK(prefs_);
+  MigrateObsoleteNotificationPref();
 
   // Read global defaults.
   DCHECK_EQ(arraysize(kTypeNames),
@@ -171,15 +173,12 @@ PrefDefaultProvider::PrefDefaultProvider(Profile* profile)
         UserMetricsAction("CookieBlockingDisabledPerDefault"));
   }
 
-  pref_change_registrar_.Init(prefs);
+  pref_change_registrar_.Init(prefs_);
   pref_change_registrar_.Add(prefs::kDefaultContentSettings, this);
-  notification_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                              Source<Profile>(profile_));
-  initializing_ = false;
 }
 
 PrefDefaultProvider::~PrefDefaultProvider() {
-  UnregisterObservers();
+  DCHECK(!prefs_);
 }
 
 ContentSetting PrefDefaultProvider::ProvideDefaultSetting(
@@ -192,6 +191,7 @@ void PrefDefaultProvider::UpdateDefaultSetting(
     ContentSettingsType content_type,
     ContentSetting setting) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(prefs_);
   DCHECK(kTypeNames[content_type] != NULL);  // Don't call this for Geolocation.
 
   // The default settings may not be directly modified for OTR sessions.
@@ -199,13 +199,11 @@ void PrefDefaultProvider::UpdateDefaultSetting(
   if (is_incognito_)
     return;
 
-  PrefService* prefs = profile_->GetPrefs();
-
   std::string dictionary_path(kTypeNames[content_type]);
-  updating_preferences_ = true;
   {
+    AutoReset<bool> auto_reset(&updating_preferences_, true);
     base::AutoLock lock(lock_);
-    DictionaryPrefUpdate update(prefs, prefs::kDefaultContentSettings);
+    DictionaryPrefUpdate update(prefs_, prefs::kDefaultContentSettings);
     DictionaryValue* default_settings_dictionary = update.Get();
     if ((setting == CONTENT_SETTING_DEFAULT) ||
         (setting == kDefaultSettings[content_type])) {
@@ -219,7 +217,6 @@ void PrefDefaultProvider::UpdateDefaultSetting(
           dictionary_path, Value::CreateIntegerValue(setting));
     }
   }
-  updating_preferences_ = false;
 
   ContentSettingsDetails details(
       ContentSettingsPattern(),
@@ -240,7 +237,7 @@ void PrefDefaultProvider::Observe(int type,
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (type == chrome::NOTIFICATION_PREF_CHANGED) {
-    DCHECK_EQ(profile_->GetPrefs(), Source<PrefService>(source).ptr());
+    DCHECK_EQ(prefs_, Source<PrefService>(source).ptr());
     if (updating_preferences_)
       return;
 
@@ -252,35 +249,27 @@ void PrefDefaultProvider::Observe(int type,
       return;
     }
 
-    if (!is_incognito_) {
-      ContentSettingsDetails details(ContentSettingsPattern(),
-                                     ContentSettingsPattern(),
-                                     CONTENT_SETTINGS_TYPE_DEFAULT,
-                                     std::string());
-      NotifyObservers(details);
-    }
-  } else if (type == chrome::NOTIFICATION_PROFILE_DESTROYED) {
-    DCHECK_EQ(profile_, Source<Profile>(source).ptr());
-    UnregisterObservers();
+    ContentSettingsDetails details(ContentSettingsPattern(),
+                                   ContentSettingsPattern(),
+                                   CONTENT_SETTINGS_TYPE_DEFAULT,
+                                   std::string());
+    NotifyObservers(details);
   } else {
     NOTREACHED() << "Unexpected notification";
   }
 }
 
-void PrefDefaultProvider::UnregisterObservers() {
+void PrefDefaultProvider::ShutdownOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
-    return;
+  DCHECK(prefs_);
   pref_change_registrar_.RemoveAll();
-  notification_registrar_.Remove(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                                 Source<Profile>(profile_));
-  profile_ = NULL;
+  prefs_ = NULL;
+  host_content_settings_map_ = NULL;
 }
 
 void PrefDefaultProvider::ReadDefaultSettings(bool overwrite) {
-  PrefService* prefs = profile_->GetPrefs();
   const DictionaryValue* default_settings_dictionary =
-      prefs->GetDictionary(prefs::kDefaultContentSettings);
+      prefs_->GetDictionary(prefs::kDefaultContentSettings);
 
   base::AutoLock lock(lock_);
 
@@ -335,20 +324,20 @@ void PrefDefaultProvider::GetSettingsFromDictionary(
 void PrefDefaultProvider::NotifyObservers(
     const ContentSettingsDetails& details) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (initializing_ || profile_ == NULL)
+  if (host_content_settings_map_ == NULL)
     return;
   NotificationService::current()->Notify(
       chrome::NOTIFICATION_CONTENT_SETTINGS_CHANGED,
-      Source<HostContentSettingsMap>(profile_->GetHostContentSettingsMap()),
+      Source<HostContentSettingsMap>(host_content_settings_map_),
       Details<const ContentSettingsDetails>(&details));
 }
 
-void PrefDefaultProvider::MigrateObsoleteNotificationPref(PrefService* prefs) {
-  if (prefs->HasPrefPath(prefs::kDesktopNotificationDefaultContentSetting)) {
+void PrefDefaultProvider::MigrateObsoleteNotificationPref() {
+  if (prefs_->HasPrefPath(prefs::kDesktopNotificationDefaultContentSetting)) {
     ContentSetting setting = IntToContentSetting(
-        prefs->GetInteger(prefs::kDesktopNotificationDefaultContentSetting));
+        prefs_->GetInteger(prefs::kDesktopNotificationDefaultContentSetting));
     UpdateDefaultSetting(CONTENT_SETTINGS_TYPE_NOTIFICATIONS, setting);
-    prefs->ClearPref(prefs::kDesktopNotificationDefaultContentSetting);
+    prefs_->ClearPref(prefs::kDesktopNotificationDefaultContentSetting);
   }
 }
 
@@ -395,28 +384,27 @@ void PrefProvider::RegisterUserPrefs(PrefService* prefs) {
                                 PrefService::UNSYNCABLE_PREF);
 }
 
-PrefProvider::PrefProvider(Profile* profile)
-  : profile_(profile),
-    is_incognito_(profile_->IsOffTheRecord()),
+PrefProvider::PrefProvider(HostContentSettingsMap* map,
+                           PrefService* prefs,
+                           bool incognito)
+  : prefs_(prefs),
+    host_content_settings_map_(map),
+    is_incognito_(incognito),
     updating_preferences_(false) {
-  Init();
-}
-
-void PrefProvider::Init() {
-  initializing_ = true;
-  PrefService* prefs = profile_->GetPrefs();
-
-  // Migrate obsolete preferences.
-  MigrateObsoletePerhostPref(prefs);
-  MigrateObsoletePopupsPref(prefs);
-  MigrateObsoleteContentSettingsPatternPref(prefs);
+  DCHECK(prefs_);
+  if (!is_incognito_) {
+    // Migrate obsolete preferences.
+    MigrateObsoletePerhostPref();
+    MigrateObsoletePopupsPref();
+    MigrateObsoleteContentSettingsPatternPref();
+  }
 
   // Verify preferences version.
-  if (!prefs->HasPrefPath(prefs::kContentSettingsVersion)) {
-    prefs->SetInteger(prefs::kContentSettingsVersion,
+  if (!prefs_->HasPrefPath(prefs::kContentSettingsVersion)) {
+    prefs_->SetInteger(prefs::kContentSettingsVersion,
                       ContentSettingsPattern::kContentSettingsPatternVersion);
   }
-  if (prefs->GetInteger(prefs::kContentSettingsVersion) >
+  if (prefs_->GetInteger(prefs::kContentSettingsVersion) >
       ContentSettingsPattern::kContentSettingsPatternVersion) {
     LOG(ERROR) << "Unknown content settings version in preferences.";
     return;
@@ -430,20 +418,16 @@ void PrefProvider::Init() {
                          value_map_.size());
   }
 
-  pref_change_registrar_.Init(prefs);
+  pref_change_registrar_.Init(prefs_);
   pref_change_registrar_.Add(prefs::kContentSettingsPatterns, this);
   pref_change_registrar_.Add(prefs::kContentSettingsPatternPairs, this);
-
-  notification_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                              Source<Profile>(profile_));
-  initializing_ = false;
 }
 
 ContentSetting PrefProvider::GetContentSetting(
-      const GURL& primary_url,
-      const GURL& secondary_url,
-      ContentSettingsType content_type,
-      const ResourceIdentifier& resource_identifier) const {
+    const GURL& primary_url,
+    const GURL& secondary_url,
+    ContentSettingsType content_type,
+    const ResourceIdentifier& resource_identifier) const {
   // For a |PrefProvider| used in a |HostContentSettingsMap| of a non incognito
   // profile, this will always return NULL.
   // TODO(markusheintz): I don't like this. I'd like to have an
@@ -469,9 +453,9 @@ ContentSetting PrefProvider::GetContentSetting(
 }
 
 void PrefProvider::GetAllContentSettingsRules(
-      ContentSettingsType content_type,
-      const ResourceIdentifier& resource_identifier,
-      Rules* content_setting_rules) const {
+    ContentSettingsType content_type,
+    const ResourceIdentifier& resource_identifier,
+    Rules* content_setting_rules) const {
   DCHECK(content_setting_rules);
   content_setting_rules->clear();
 
@@ -500,8 +484,9 @@ void PrefProvider::SetContentSetting(
     ContentSettingsType content_type,
     const ResourceIdentifier& resource_identifier,
     ContentSetting setting) {
-  DCHECK(kTypeNames[content_type] != NULL);  // Don't call this for Geolocation.
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(prefs_);
+  DCHECK(kTypeNames[content_type] != NULL);  // Don't call this for Geolocation.
 
   // Update in memory value map.
   OriginIdentifierValueMap* map_to_modify = &incognito_value_map_;
@@ -527,7 +512,7 @@ void PrefProvider::SetContentSetting(
   }
 
   // Update the content settings preference.
-  if (!is_incognito_ && profile_) {
+  if (!is_incognito_) {
     UpdatePref(primary_pattern,
                secondary_pattern,
                content_type,
@@ -536,13 +521,15 @@ void PrefProvider::SetContentSetting(
   }
 
   ContentSettingsDetails details(
-      primary_pattern, secondary_pattern, content_type, std::string());
+      primary_pattern, secondary_pattern, content_type, resource_identifier);
   NotifyObservers(details);
 }
 
 void PrefProvider::ClearAllContentSettingsRules(
     ContentSettingsType content_type) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(kTypeNames[content_type] != NULL);  // Don't call this for Geolocation.
+  DCHECK(prefs_);
 
   OriginIdentifierValueMap* map_to_modify = &incognito_value_map_;
   if (!is_incognito_)
@@ -582,41 +569,35 @@ void PrefProvider::Observe(
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (type == chrome::NOTIFICATION_PREF_CHANGED) {
-    DCHECK_EQ(profile_->GetPrefs(), Source<PrefService>(source).ptr());
+    DCHECK_EQ(prefs_, Source<PrefService>(source).ptr());
     if (updating_preferences_)
       return;
 
     std::string* name = Details<std::string>(details).ptr();
     if (*name == prefs::kContentSettingsPatternPairs) {
-      SyncObsoletePref(profile_->GetPrefs());
+      SyncObsoletePref();
       ReadContentSettingsFromPref(true);
     } else if (*name == prefs::kContentSettingsPatterns) {
-      updating_preferences_ = true;
-      MigrateObsoleteContentSettingsPatternPref(profile_->GetPrefs());
-      updating_preferences_ = false;
+      AutoReset<bool> auto_reset(&updating_preferences_, true);
+      MigrateObsoleteContentSettingsPatternPref();
       ReadContentSettingsFromPref(true);
     } else {
       NOTREACHED() << "Unexpected preference observed";
       return;
     }
 
-    if (!is_incognito_) {
-      ContentSettingsDetails details(ContentSettingsPattern(),
-                                     ContentSettingsPattern(),
-                                     CONTENT_SETTINGS_TYPE_DEFAULT,
-                                     std::string());
-      NotifyObservers(details);
-    }
-  } else if (type == chrome::NOTIFICATION_PROFILE_DESTROYED) {
-    DCHECK_EQ(profile_, Source<Profile>(source).ptr());
-    UnregisterObservers();
+    ContentSettingsDetails details(ContentSettingsPattern(),
+                                   ContentSettingsPattern(),
+                                   CONTENT_SETTINGS_TYPE_DEFAULT,
+                                   std::string());
+    NotifyObservers(details);
   } else {
     NOTREACHED() << "Unexpected notification";
   }
 }
 
 PrefProvider::~PrefProvider() {
-  UnregisterObservers();
+  DCHECK(!prefs_);
 }
 
 // ////////////////////////////////////////////////////////////////////////////
@@ -628,7 +609,7 @@ void PrefProvider::UpdatePref(
     ContentSettingsType content_type,
     const ResourceIdentifier& resource_identifier,
     ContentSetting setting) {
-  updating_preferences_ = true;
+  AutoReset<bool> auto_reset(&updating_preferences_, true);
   UpdatePatternPairsPref(primary_pattern,
                          secondary_pattern,
                          content_type,
@@ -639,23 +620,21 @@ void PrefProvider::UpdatePref(
                      content_type,
                      resource_identifier,
                      setting);
-  updating_preferences_ = false;
 }
 
 void PrefProvider::ReadContentSettingsFromPref(bool overwrite) {
   base::AutoLock auto_lock(lock_);
 
-  PrefService* prefs = profile_->GetPrefs();
   const DictionaryValue* all_settings_dictionary =
-      prefs->GetDictionary(prefs::kContentSettingsPatternPairs);
+      prefs_->GetDictionary(prefs::kContentSettingsPatternPairs);
 
   if (overwrite)
     value_map_.clear();
 
-  updating_preferences_ = true;
+  AutoReset<bool> auto_reset(&updating_preferences_, true);
   // Careful: The returned value could be NULL if the pref has never been set.
   if (all_settings_dictionary != NULL) {
-    DictionaryPrefUpdate update(prefs, prefs::kContentSettingsPatternPairs);
+    DictionaryPrefUpdate update(prefs_, prefs::kContentSettingsPatternPairs);
     DictionaryValue* mutable_settings;
     scoped_ptr<DictionaryValue> mutable_settings_scope;
 
@@ -733,7 +712,6 @@ void PrefProvider::ReadContentSettingsFromPref(bool overwrite) {
       }
     }
   }
-  updating_preferences_ = false;
 }
 
 void PrefProvider::UpdatePatternsPref(
@@ -742,7 +720,7 @@ void PrefProvider::UpdatePatternsPref(
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       ContentSetting setting) {
-  DictionaryPrefUpdate update(profile_->GetPrefs(),
+  DictionaryPrefUpdate update(prefs_,
                               prefs::kContentSettingsPatterns);
   DictionaryValue* all_settings_dictionary = update.Get();
 
@@ -808,13 +786,13 @@ void PrefProvider::UpdatePatternPairsPref(
       ContentSettingsType content_type,
       const ResourceIdentifier& resource_identifier,
       ContentSetting setting) {
-  DictionaryPrefUpdate update(profile_->GetPrefs(),
+  DictionaryPrefUpdate update(prefs_,
                               prefs::kContentSettingsPatternPairs);
   DictionaryValue* all_settings_dictionary = update.Get();
 
   // Get settings dictionary for the given patterns.
   std::string pattern_str(CreatePatternString(primary_pattern,
-                                            secondary_pattern));
+                                              secondary_pattern));
   DictionaryValue* settings_dictionary = NULL;
   bool found = all_settings_dictionary->GetDictionaryWithoutPathExpansion(
       pattern_str, &settings_dictionary);
@@ -869,6 +847,7 @@ void PrefProvider::UpdatePatternPairsPref(
   }
 }
 
+// static
 void PrefProvider::CanonicalizeContentSettingsExceptions(
     DictionaryValue* all_settings_dictionary) {
   DCHECK(all_settings_dictionary);
@@ -921,29 +900,25 @@ void PrefProvider::CanonicalizeContentSettingsExceptions(
 void PrefProvider::NotifyObservers(
     const ContentSettingsDetails& details) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (initializing_ || profile_ == NULL)
-    return;
+  DCHECK(host_content_settings_map_);
   NotificationService::current()->Notify(
       chrome::NOTIFICATION_CONTENT_SETTINGS_CHANGED,
-      Source<HostContentSettingsMap>(
-          profile_->GetHostContentSettingsMap()),
+      Source<HostContentSettingsMap>(host_content_settings_map_),
       Details<const ContentSettingsDetails>(&details));
 }
 
-void PrefProvider::UnregisterObservers() {
+void PrefProvider::ShutdownOnUIThread() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
-    return;
+  DCHECK(prefs_);
   pref_change_registrar_.RemoveAll();
-  notification_registrar_.Remove(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                                 Source<Profile>(profile_));
-  profile_ = NULL;
+  prefs_ = NULL;
+  host_content_settings_map_ = NULL;
 }
 
-void PrefProvider::MigrateObsoletePerhostPref(PrefService* prefs) {
-  if (prefs->HasPrefPath(prefs::kPerHostContentSettings)) {
+void PrefProvider::MigrateObsoletePerhostPref() {
+  if (prefs_->HasPrefPath(prefs::kPerHostContentSettings)) {
     const DictionaryValue* all_settings_dictionary =
-        prefs->GetDictionary(prefs::kPerHostContentSettings);
+        prefs_->GetDictionary(prefs::kPerHostContentSettings);
     DCHECK(all_settings_dictionary);
     for (DictionaryValue::key_iterator
          i(all_settings_dictionary->begin_keys());
@@ -995,14 +970,14 @@ void PrefProvider::MigrateObsoletePerhostPref(PrefService* prefs) {
         }
       }
     }
-    prefs->ClearPref(prefs::kPerHostContentSettings);
+    prefs_->ClearPref(prefs::kPerHostContentSettings);
   }
 }
 
-void PrefProvider::MigrateObsoletePopupsPref(PrefService* prefs) {
-  if (prefs->HasPrefPath(prefs::kPopupWhitelistedHosts)) {
+void PrefProvider::MigrateObsoletePopupsPref() {
+  if (prefs_->HasPrefPath(prefs::kPopupWhitelistedHosts)) {
     const ListValue* whitelist_pref =
-        prefs->GetList(prefs::kPopupWhitelistedHosts);
+        prefs_->GetList(prefs::kPopupWhitelistedHosts);
     for (ListValue::const_iterator i(whitelist_pref->begin());
          i != whitelist_pref->end(); ++i) {
       std::string host;
@@ -1013,18 +988,16 @@ void PrefProvider::MigrateObsoletePopupsPref(PrefService* prefs) {
                         "",
                         CONTENT_SETTING_ALLOW);
     }
-    prefs->ClearPref(prefs::kPopupWhitelistedHosts);
+    prefs_->ClearPref(prefs::kPopupWhitelistedHosts);
   }
 }
 
-void PrefProvider::MigrateObsoleteContentSettingsPatternPref(
-    PrefService* prefs) {
-  if (prefs->HasPrefPath(prefs::kContentSettingsPatterns) &&
-      !is_incognito_) {
+void PrefProvider::MigrateObsoleteContentSettingsPatternPref() {
+  if (prefs_->HasPrefPath(prefs::kContentSettingsPatterns) && !is_incognito_) {
     const DictionaryValue* all_settings_dictionary =
-      prefs->GetDictionary(prefs::kContentSettingsPatterns);
+      prefs_->GetDictionary(prefs::kContentSettingsPatterns);
 
-    DictionaryPrefUpdate update(prefs, prefs::kContentSettingsPatternPairs);
+    DictionaryPrefUpdate update(prefs_, prefs::kContentSettingsPatternPairs);
     DictionaryValue* exceptions_dictionary;
     exceptions_dictionary = update.Get();
     for (DictionaryValue::key_iterator i(all_settings_dictionary->begin_keys());
@@ -1057,14 +1030,14 @@ void PrefProvider::MigrateObsoleteContentSettingsPatternPref(
   }
 }
 
-void PrefProvider::SyncObsoletePref(PrefService* prefs) {
-  updating_preferences_ = true;
-  if (prefs->HasPrefPath(prefs::kContentSettingsPatternPairs) &&
+void PrefProvider::SyncObsoletePref() {
+  AutoReset<bool> auto_reset(&updating_preferences_, true);
+  if (prefs_->HasPrefPath(prefs::kContentSettingsPatternPairs) &&
       !is_incognito_) {
     const DictionaryValue* pattern_pairs_dictionary =
-      prefs->GetDictionary(prefs::kContentSettingsPatternPairs);
+      prefs_->GetDictionary(prefs::kContentSettingsPatternPairs);
 
-    DictionaryPrefUpdate update(prefs, prefs::kContentSettingsPatterns);
+    DictionaryPrefUpdate update(prefs_, prefs::kContentSettingsPatterns);
     DictionaryValue* obsolete_settings_dictionary = update.Get();
 
     for (DictionaryValue::key_iterator i =
@@ -1089,7 +1062,6 @@ void PrefProvider::SyncObsoletePref(PrefService* prefs) {
           new_key, dictionary->DeepCopy());
     }
   }
-  updating_preferences_ = false;
 }
 
 }  // namespace content_settings
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.h b/chrome/browser/content_settings/content_settings_pref_provider.h
index 89d1e93..6320568 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.h
+++ b/chrome/browser/content_settings/content_settings_pref_provider.h
@@ -23,8 +23,8 @@
 
 class ContentSettingsDetails;
 class DictionaryValue;
+class HostContentSettingsMap;
 class PrefService;
-class Profile;
 
 namespace content_settings {
 
@@ -33,7 +33,9 @@ namespace content_settings {
 class PrefDefaultProvider : public DefaultProviderInterface,
                             public NotificationObserver {
  public:
-  explicit PrefDefaultProvider(Profile* profile);
+  PrefDefaultProvider(HostContentSettingsMap* map,
+                      PrefService* prefs,
+                      bool incognito);
   virtual ~PrefDefaultProvider();
 
   // DefaultContentSettingsProvider implementation.
@@ -43,6 +45,8 @@ class PrefDefaultProvider : public DefaultProviderInterface,
                                     ContentSetting setting);
   virtual bool DefaultSettingIsManaged(ContentSettingsType content_type) const;
 
+  void ShutdownOnUIThread();
+
   static void RegisterUserPrefs(PrefService* prefs);
 
   // NotificationObserver implementation.
@@ -57,8 +61,6 @@ class PrefDefaultProvider : public DefaultProviderInterface,
   // mutex deadlock.
   void NotifyObservers(const ContentSettingsDetails& details);
 
-  void UnregisterObservers();
-
   // Sets the fields of |settings| based on the values in |dictionary|.
   void GetSettingsFromDictionary(const DictionaryValue* dictionary,
                                  ContentSettings* settings);
@@ -71,12 +73,13 @@ class PrefDefaultProvider : public DefaultProviderInterface,
   // true and the preference is missing, the local copy will be cleared as well.
   void ReadDefaultSettings(bool overwrite);
 
-  void MigrateObsoleteNotificationPref(PrefService* prefs);
+  void MigrateObsoleteNotificationPref();
 
   // Copies of the pref data, so that we can read it on the IO thread.
   ContentSettings default_content_settings_;
 
-  Profile* profile_;
+  HostContentSettingsMap* host_content_settings_map_;
+  PrefService* prefs_;
 
   // Whether this settings map is for an Incognito session.
   bool is_incognito_;
@@ -86,14 +89,11 @@ class PrefDefaultProvider : public DefaultProviderInterface,
   mutable base::Lock lock_;
 
   PrefChangeRegistrar pref_change_registrar_;
-  NotificationRegistrar notification_registrar_;
 
   // Whether we are currently updating preferences, this is used to ignore
   // notifications from the preferences service that we triggered ourself.
   bool updating_preferences_;
 
-  bool initializing_;
-
   DISALLOW_COPY_AND_ASSIGN(PrefDefaultProvider);
 };
 
@@ -104,7 +104,9 @@ class PrefProvider : public ProviderInterface,
  public:
   static void RegisterUserPrefs(PrefService* prefs);
 
-  explicit PrefProvider(Profile* profile);
+  PrefProvider(HostContentSettingsMap* map,
+               PrefService* prefs,
+               bool incognito);
   virtual ~PrefProvider();
 
   // ProviderInterface implementations.
@@ -129,6 +131,8 @@ class PrefProvider : public ProviderInterface,
   virtual void ClearAllContentSettingsRules(
       ContentSettingsType content_type);
 
+  virtual void ShutdownOnUIThread();
+
   // NotificationObserver implementation.
   virtual void Observe(int type,
                        const NotificationSource& source,
@@ -172,37 +176,35 @@ class PrefProvider : public ProviderInterface,
 
   // Various migration methods (old cookie, popup and per-host data gets
   // migrated to the new format).
-  void MigrateObsoletePerhostPref(PrefService* prefs);
-  void MigrateObsoletePopupsPref(PrefService* prefs);
-  void MigrateObsoleteContentSettingsPatternPref(PrefService* prefs);
+  void MigrateObsoletePerhostPref();
+  void MigrateObsoletePopupsPref();
+  void MigrateObsoleteContentSettingsPatternPref();
 
   // Copies the value of the preference that stores the content settings
   // exceptions to the obsolete preference for content settings exceptions. This
   // is necessary to allow content settings exceptions beeing synced to older
   // versions of chrome that only use the obsolete.
-  void SyncObsoletePref(PrefService* pref);
+  void SyncObsoletePref();
 
-  void CanonicalizeContentSettingsExceptions(
+  static void CanonicalizeContentSettingsExceptions(
       DictionaryValue* all_settings_dictionary);
 
   void NotifyObservers(const ContentSettingsDetails& details);
 
-  void UnregisterObservers();
+  // Weak; owned by the Profile and reset in ShutdownOnUIThread.
+  PrefService* prefs_;
 
-  Profile* profile_;
+  // Weak; owns us
+  HostContentSettingsMap* host_content_settings_map_;
 
   bool is_incognito_;
 
   PrefChangeRegistrar pref_change_registrar_;
-  NotificationRegistrar notification_registrar_;
 
   // Whether we are currently updating preferences, this is used to ignore
   // notifications from the preferences service that we triggered ourself.
   bool updating_preferences_;
 
-  // Do not fire any Notifications as long as we are in the constructor.
-  bool initializing_;
-
   OriginIdentifierValueMap value_map_;
 
   OriginIdentifierValueMap incognito_value_map_;
diff --git a/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc b/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
index df3b8708..9ff4e38 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
@@ -30,63 +30,63 @@ namespace content_settings {
 class PrefDefaultProviderTest : public TestingBrowserProcessTest {
  public:
   PrefDefaultProviderTest()
-      : ui_thread_(BrowserThread::UI, &message_loop_) {
+      : ui_thread_(BrowserThread::UI, &message_loop_),
+        provider_(profile_.GetHostContentSettingsMap(),
+                  profile_.GetPrefs(),
+                  false) {
+  }
+  ~PrefDefaultProviderTest() {
+    provider_.ShutdownOnUIThread();
   }
 
  protected:
   MessageLoop message_loop_;
   BrowserThread ui_thread_;
+  TestingProfile profile_;
+  PrefDefaultProvider provider_;
 };
 
 TEST_F(PrefDefaultProviderTest, DefaultValues) {
-  TestingProfile profile;
-  content_settings::PrefDefaultProvider provider(&profile);
-
   ASSERT_FALSE(
-      provider.DefaultSettingIsManaged(CONTENT_SETTINGS_TYPE_COOKIES));
+      provider_.DefaultSettingIsManaged(CONTENT_SETTINGS_TYPE_COOKIES));
 
   // Check setting defaults.
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
-  provider.UpdateDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES,
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+  provider_.UpdateDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES,
                                 CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
 }
 
 TEST_F(PrefDefaultProviderTest, Observer) {
-  TestingProfile profile;
-  PrefDefaultProvider provider(&profile);
   MockSettingsObserver observer;
 
   EXPECT_CALL(observer,
-              OnContentSettingsChanged(profile.GetHostContentSettingsMap(),
+              OnContentSettingsChanged(profile_.GetHostContentSettingsMap(),
                                        CONTENT_SETTINGS_TYPE_IMAGES, false,
                                        _, _, true));
   // Expect a second call because the PrefDefaultProvider in the TestingProfile
   // also observes the default content settings preference.
   EXPECT_CALL(observer,
-              OnContentSettingsChanged(profile.GetHostContentSettingsMap(),
+              OnContentSettingsChanged(profile_.GetHostContentSettingsMap(),
                                        CONTENT_SETTINGS_TYPE_DEFAULT, true,
                                        _, _, true));
-  provider.UpdateDefaultSetting(
+  provider_.UpdateDefaultSetting(
       CONTENT_SETTINGS_TYPE_IMAGES, CONTENT_SETTING_BLOCK);
 }
 
 TEST_F(PrefDefaultProviderTest, ObserveDefaultPref) {
-  TestingProfile profile;
-  PrefDefaultProvider provider(&profile);
-
-  PrefService* prefs = profile.GetPrefs();
+  PrefService* prefs = profile_.GetPrefs();
 
   // Make a copy of the default pref value so we can reset it later.
   scoped_ptr<Value> default_value(prefs->FindPreference(
       prefs::kDefaultContentSettings)->GetValue()->DeepCopy());
 
-  provider.UpdateDefaultSetting(
+  provider_.UpdateDefaultSetting(
       CONTENT_SETTINGS_TYPE_COOKIES, CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
 
   // Make a copy of the pref's new value so we can reset it later.
   scoped_ptr<Value> new_value(prefs->FindPreference(
@@ -95,33 +95,30 @@ TEST_F(PrefDefaultProviderTest, ObserveDefaultPref) {
   // Clearing the backing pref should also clear the internal cache.
   prefs->Set(prefs::kDefaultContentSettings, *default_value);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
 
   // Reseting the pref to its previous value should update the cache.
   prefs->Set(prefs::kDefaultContentSettings, *new_value);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
 }
 
 TEST_F(PrefDefaultProviderTest, OffTheRecord) {
-  TestingProfile profile;
-  PrefDefaultProvider provider(&profile);
-
-  profile.set_incognito(true);
-  PrefDefaultProvider otr_provider(&profile);
-  profile.set_incognito(false);
+  PrefDefaultProvider otr_provider(profile_.GetHostContentSettingsMap(),
+                                   profile_.GetPrefs(),
+                                   true);
 
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             otr_provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
 
   // Changing content settings on the main provider should also affect the
   // incognito map.
-  provider.UpdateDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES,
+  provider_.UpdateDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES,
                                 CONTENT_SETTING_BLOCK);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             otr_provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
 
@@ -129,9 +126,11 @@ TEST_F(PrefDefaultProviderTest, OffTheRecord) {
   otr_provider.UpdateDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES,
                                    CONTENT_SETTING_ALLOW);
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
-            provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+            provider_.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             otr_provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
+
+  otr_provider.ShutdownOnUIThread();
 }
 
 // ////////////////////////////////////////////////////////////////////////////
@@ -160,17 +159,8 @@ class PrefProviderTest : public TestingBrowserProcessTest {
 
 TEST_F(PrefProviderTest, Observer) {
   TestingProfile profile;
-  // Get the |HostContentSettingsMap| one time in order to initialize it.
-  // Otherwise we end up in a dead lock when the |PrefProvider| tries to notify
-  // content settings change observers. The |PrefProvider| set's the
-  // |HostContentSettingsMap| as notification source and would trigger in
-  // infinite recursive instantiation loop.
-  // TODO(markusheintz): Let the HostContentSettingsMap sent out notifications.
-  // Providers and HostContentSettingsMap should communicate via a observer
-  // pattern.
-  profile.GetHostContentSettingsMap();
-  Profile* p = &profile;
-  PrefProvider pref_content_settings_provider(p);
+  PrefProvider pref_content_settings_provider(
+      profile.GetHostContentSettingsMap(), profile.GetPrefs(), false);
   MockSettingsObserver observer;
   ContentSettingsPattern pattern =
       ContentSettingsPattern::FromString("[*.]example.com");
@@ -198,6 +188,8 @@ TEST_F(PrefProviderTest, Observer) {
       CONTENT_SETTINGS_TYPE_IMAGES,
       "",
       CONTENT_SETTING_ALLOW);
+
+  pref_content_settings_provider.ShutdownOnUIThread();
 }
 
 // Test for regression in which the PrefProvider modified the user pref store
@@ -224,10 +216,11 @@ TEST_F(PrefProviderTest, Incognito) {
   profile.SetPrefService(regular_prefs);
   otr_profile->set_incognito(true);
   otr_profile->SetPrefService(otr_prefs);
-  profile.GetHostContentSettingsMap();
 
-  PrefProvider pref_content_settings_provider(&profile);
-  PrefProvider pref_content_settings_provider_incognito(otr_profile);
+  PrefProvider pref_content_settings_provider(
+      profile.GetHostContentSettingsMap(), regular_prefs, false);
+  PrefProvider pref_content_settings_provider_incognito(
+      otr_profile->GetHostContentSettingsMap(), otr_prefs, true);
   ContentSettingsPattern pattern =
       ContentSettingsPattern::FromString("[*.]example.com");
   pref_content_settings_provider.SetContentSetting(
@@ -248,13 +241,16 @@ TEST_F(PrefProviderTest, Incognito) {
                 host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
   // But the value should not be overridden in the OTR user prefs accidentally.
   EXPECT_FALSE(otr_user_prefs->IsSetInOverlay(prefs::kContentSettingsPatterns));
+
+  pref_content_settings_provider.ShutdownOnUIThread();
+  pref_content_settings_provider_incognito.ShutdownOnUIThread();
 }
 
 TEST_F(PrefProviderTest, Patterns) {
   TestingProfile testing_profile;
-  testing_profile.GetHostContentSettingsMap();
   PrefProvider pref_content_settings_provider(
-      testing_profile.GetOriginalProfile());
+      testing_profile.GetHostContentSettingsMap(),
+      testing_profile.GetPrefs(), false);
 
   GURL host1("http://example.com/");
   GURL host2("http://www.example.com/");
@@ -308,6 +304,8 @@ TEST_F(PrefProviderTest, Patterns) {
   EXPECT_EQ(CONTENT_SETTING_BLOCK,
             pref_content_settings_provider.GetContentSetting(
                 host4, host4, CONTENT_SETTINGS_TYPE_IMAGES, ""));
+
+  pref_content_settings_provider.ShutdownOnUIThread();
 }
 
 TEST_F(PrefProviderTest, ResourceIdentifier) {
@@ -317,9 +315,10 @@ TEST_F(PrefProviderTest, ResourceIdentifier) {
   cmd->AppendSwitch(switches::kEnableResourceContentSettings);
 
   TestingProfile testing_profile;
-  testing_profile.GetHostContentSettingsMap();
   PrefProvider pref_content_settings_provider(
-      testing_profile.GetOriginalProfile());
+      testing_profile.GetHostContentSettingsMap(),
+      testing_profile.GetPrefs(),
+      false);
 
   GURL host("http://example.com/");
   ContentSettingsPattern pattern =
@@ -342,6 +341,8 @@ TEST_F(PrefProviderTest, ResourceIdentifier) {
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
             pref_content_settings_provider.GetContentSetting(
                 host, host, CONTENT_SETTINGS_TYPE_PLUGINS, resource2));
+
+  pref_content_settings_provider.ShutdownOnUIThread();
 }
 
 TEST_F(PrefProviderTest, MigrateSinglePatternSettings) {
@@ -364,7 +365,8 @@ TEST_F(PrefProviderTest, MigrateSinglePatternSettings) {
   prefs->Set(prefs::kContentSettingsPatterns, *all_settings_dictionary);
 
   // Test if single pattern settings are properly migrated.
-  content_settings::PrefProvider provider(profile.GetOriginalProfile());
+  content_settings::PrefProvider provider(profile.GetHostContentSettingsMap(),
+                                          prefs, false);
 
   // Validate migrated preferences
   const DictionaryValue* const_all_settings_dictionary =
@@ -386,6 +388,8 @@ TEST_F(PrefProviderTest, MigrateSinglePatternSettings) {
       GURL("http://www.example.com"),
       CONTENT_SETTINGS_TYPE_POPUPS,
       ""));
+
+  provider.ShutdownOnUIThread();
 }
 
 }  // namespace content_settings
diff --git a/chrome/browser/content_settings/content_settings_provider.h b/chrome/browser/content_settings/content_settings_provider.h
index b94697b..8065dbe 100644
--- a/chrome/browser/content_settings/content_settings_provider.h
+++ b/chrome/browser/content_settings/content_settings_provider.h
@@ -42,6 +42,8 @@ class DefaultProviderInterface {
   // there shouldn't be any UI shown to modify this setting.
   virtual bool DefaultSettingIsManaged(
       ContentSettingsType content_type) const = 0;
+
+  virtual void ShutdownOnUIThread() = 0;
 };
 
 class ProviderInterface {
@@ -103,7 +105,7 @@ class ProviderInterface {
 
   // Resets all content settings for the given |content_type| to
   // CONTENT_SETTING_DEFAULT. For content types that require a resource
-  // identifier all content settings for any resource identifieres of the given
+  // identifier all content settings for any resource identifiers of the given
   // |content_type| will be reset to CONTENT_SETTING_DEFAULT.
   //
   // This should only be called on the UI thread, and not after
@@ -115,7 +117,7 @@ class ProviderInterface {
   // This methods needs to be called before destroying the Profile.
   // Afterwards, none of the methods above that should only be called on the UI
   // thread should be called anymore.
-  virtual void ShutdownOnUIThread() {}
+  virtual void ShutdownOnUIThread() = 0;
 };
 
 }  // namespace content_settings
diff --git a/chrome/browser/content_settings/content_settings_provider_unittest.cc b/chrome/browser/content_settings/content_settings_provider_unittest.cc
index 0b41475..3155430 100644
--- a/chrome/browser/content_settings/content_settings_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_provider_unittest.cc
@@ -11,9 +11,9 @@ namespace content_settings {
 
 TEST(ContentSettingsProviderTest, Mock) {
   MockDefaultProvider provider(CONTENT_SETTINGS_TYPE_COOKIES,
-                                       CONTENT_SETTING_ALLOW,
-                                       false,
-                                       true);
+                               CONTENT_SETTING_ALLOW,
+                               false,
+                               true);
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             provider.ProvideDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES));
   EXPECT_EQ(CONTENT_SETTING_DEFAULT,
diff --git a/chrome/browser/content_settings/host_content_settings_map.cc b/chrome/browser/content_settings/host_content_settings_map.cc
index f8c3484..e0e1e56 100644
--- a/chrome/browser/content_settings/host_content_settings_map.cc
+++ b/chrome/browser/content_settings/host_content_settings_map.cc
@@ -68,9 +68,12 @@ const char* kProviderNames[] = {
 
 }  // namespace
 
-HostContentSettingsMap::HostContentSettingsMap(Profile* profile)
-    : profile_(profile),
-      is_off_the_record_(profile_->IsOffTheRecord()),
+HostContentSettingsMap::HostContentSettingsMap(
+    PrefService* prefs,
+    ExtensionService* extension_service,
+    bool incognito)
+    : prefs_(prefs),
+      is_off_the_record_(incognito),
       updating_preferences_(false),
       block_third_party_cookies_(false),
       is_block_third_party_cookies_managed_(false) {
@@ -78,21 +81,20 @@ HostContentSettingsMap::HostContentSettingsMap(Profile* profile)
   // critical, as providers that are further down in the list (i.e. added later)
   // override providers further up.
   default_content_settings_providers_.push_back(
-      make_linked_ptr(new content_settings::PrefDefaultProvider(profile)));
+      make_linked_ptr(new content_settings::PrefDefaultProvider(
+          this, prefs_, is_off_the_record_)));
   content_settings::DefaultProviderInterface* policy_default_provider =
-      new content_settings::PolicyDefaultProvider(profile);
+      new content_settings::PolicyDefaultProvider(this, prefs_);
   default_content_settings_providers_.push_back(
       make_linked_ptr(policy_default_provider));
 
-  PrefService* prefs = profile_->GetPrefs();
-
   // TODO(markusheintz): Discuss whether it is sensible to move migration code
   // to PrefContentSettingsProvider.
-  MigrateObsoleteCookiePref(prefs);
+  MigrateObsoleteCookiePref();
 
   // Read misc. global settings.
   block_third_party_cookies_ =
-      prefs->GetBoolean(prefs::kBlockThirdPartyCookies);
+      prefs_->GetBoolean(prefs::kBlockThirdPartyCookies);
   if (block_third_party_cookies_) {
     UserMetrics::RecordAction(
         UserMetricsAction("ThirdPartyCookieBlockingEnabled"));
@@ -101,15 +103,16 @@ HostContentSettingsMap::HostContentSettingsMap(Profile* profile)
         UserMetricsAction("ThirdPartyCookieBlockingDisabled"));
   }
   is_block_third_party_cookies_managed_ =
-      prefs->IsManagedPreference(prefs::kBlockThirdPartyCookies);
+      prefs_->IsManagedPreference(prefs::kBlockThirdPartyCookies);
 
   // User defined non default content settings are provided by the PrefProvider.
   // The order in which the content settings providers are created is critical,
   // as providers that are further up in the list (i.e. added earlier) override
   // providers further down.
   content_settings_providers_.push_back(make_linked_ptr(
-      new content_settings::PolicyProvider(profile, policy_default_provider)));
-  ExtensionService* extension_service = profile->GetExtensionService();
+      new content_settings::PolicyProvider(this,
+                                           prefs_,
+                                           policy_default_provider)));
   if (extension_service) {
     // |extension_service| can be NULL in unit tests.
     content_settings_providers_.push_back(make_linked_ptr(
@@ -118,13 +121,11 @@ HostContentSettingsMap::HostContentSettingsMap(Profile* profile)
             extension_service->GetExtensionContentSettingsStore(),
             is_off_the_record_)));
   }
-  content_settings_providers_.push_back(
-      make_linked_ptr(new content_settings::PrefProvider(profile)));
+  content_settings_providers_.push_back(make_linked_ptr(
+      new content_settings::PrefProvider(this, prefs_, is_off_the_record_)));
 
-  pref_change_registrar_.Init(prefs);
+  pref_change_registrar_.Init(prefs_);
   pref_change_registrar_.Add(prefs::kBlockThirdPartyCookies, this);
-  notification_registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                              Source<Profile>(profile_));
 }
 
 // static
@@ -422,6 +423,7 @@ bool HostContentSettingsMap::IsSettingAllowedForType(
 
 void HostContentSettingsMap::SetBlockThirdPartyCookies(bool block) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(prefs_);
 
   // This setting may not be directly modified for OTR sessions.  Instead, it
   // is synced to the main profile's setting.
@@ -430,10 +432,9 @@ void HostContentSettingsMap::SetBlockThirdPartyCookies(bool block) {
     return;
   }
 
-  PrefService* prefs = profile_->GetPrefs();
   // If the preference block-third-party-cookies is managed then do not allow to
   // change it.
-  if (prefs->IsManagedPreference(prefs::kBlockThirdPartyCookies)) {
+  if (prefs_->IsManagedPreference(prefs::kBlockThirdPartyCookies)) {
     NOTREACHED();
     return;
   }
@@ -443,7 +444,7 @@ void HostContentSettingsMap::SetBlockThirdPartyCookies(bool block) {
     block_third_party_cookies_ = block;
   }
 
-  profile_->GetPrefs()->SetBoolean(prefs::kBlockThirdPartyCookies, block);
+  prefs_->SetBoolean(prefs::kBlockThirdPartyCookies, block);
 }
 
 void HostContentSettingsMap::Observe(int type,
@@ -452,32 +453,29 @@ void HostContentSettingsMap::Observe(int type,
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (type == chrome::NOTIFICATION_PREF_CHANGED) {
-    DCHECK_EQ(profile_->GetPrefs(), Source<PrefService>(source).ptr());
+    DCHECK_EQ(prefs_, Source<PrefService>(source).ptr());
     if (updating_preferences_)
       return;
 
     std::string* name = Details<std::string>(details).ptr();
     if (*name == prefs::kBlockThirdPartyCookies) {
       base::AutoLock auto_lock(lock_);
-      block_third_party_cookies_ = profile_->GetPrefs()->GetBoolean(
+      block_third_party_cookies_ = prefs_->GetBoolean(
           prefs::kBlockThirdPartyCookies);
       is_block_third_party_cookies_managed_ =
-          profile_->GetPrefs()->IsManagedPreference(
+          prefs_->IsManagedPreference(
               prefs::kBlockThirdPartyCookies);
     } else {
       NOTREACHED() << "Unexpected preference observed";
       return;
     }
-  } else if (type == chrome::NOTIFICATION_PROFILE_DESTROYED) {
-    DCHECK_EQ(profile_, Source<Profile>(source).ptr());
-    UnregisterObservers();
   } else {
     NOTREACHED() << "Unexpected notification";
   }
 }
 
 HostContentSettingsMap::~HostContentSettingsMap() {
-  UnregisterObservers();
+  DCHECK(!prefs_);
 }
 
 bool HostContentSettingsMap::IsDefaultContentSettingManaged(
@@ -492,33 +490,32 @@ bool HostContentSettingsMap::IsDefaultContentSettingManaged(
 }
 
 void HostContentSettingsMap::ShutdownOnUIThread() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(prefs_);
+  pref_change_registrar_.RemoveAll();
+  prefs_ = NULL;
   for (ProviderIterator it = content_settings_providers_.begin();
        it != content_settings_providers_.end();
        ++it) {
     (*it)->ShutdownOnUIThread();
   }
+  for (DefaultProviderIterator it = default_content_settings_providers_.begin();
+       it != default_content_settings_providers_.end();
+       ++it) {
+    (*it)->ShutdownOnUIThread();
+  }
 }
 
-void HostContentSettingsMap::UnregisterObservers() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (!profile_)
-    return;
-  pref_change_registrar_.RemoveAll();
-  notification_registrar_.Remove(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
-                                 Source<Profile>(profile_));
-  profile_ = NULL;
-}
-
-void HostContentSettingsMap::MigrateObsoleteCookiePref(PrefService* prefs) {
-  if (prefs->HasPrefPath(prefs::kCookieBehavior)) {
-    int cookie_behavior = prefs->GetInteger(prefs::kCookieBehavior);
-    prefs->ClearPref(prefs::kCookieBehavior);
-    if (!prefs->HasPrefPath(prefs::kDefaultContentSettings)) {
+void HostContentSettingsMap::MigrateObsoleteCookiePref() {
+  if (prefs_->HasPrefPath(prefs::kCookieBehavior)) {
+    int cookie_behavior = prefs_->GetInteger(prefs::kCookieBehavior);
+    prefs_->ClearPref(prefs::kCookieBehavior);
+    if (!prefs_->HasPrefPath(prefs::kDefaultContentSettings)) {
         SetDefaultContentSetting(CONTENT_SETTINGS_TYPE_COOKIES,
             (cookie_behavior == net::StaticCookiePolicy::BLOCK_ALL_COOKIES) ?
                 CONTENT_SETTING_BLOCK : CONTENT_SETTING_ALLOW);
     }
-    if (!prefs->HasPrefPath(prefs::kBlockThirdPartyCookies)) {
+    if (!prefs_->HasPrefPath(prefs::kBlockThirdPartyCookies)) {
       SetBlockThirdPartyCookies(cookie_behavior ==
           net::StaticCookiePolicy::BLOCK_SETTING_THIRD_PARTY_COOKIES);
     }
diff --git a/chrome/browser/content_settings/host_content_settings_map.h b/chrome/browser/content_settings/host_content_settings_map.h
index f3046ad..10fda10 100644
--- a/chrome/browser/content_settings/host_content_settings_map.h
+++ b/chrome/browser/content_settings/host_content_settings_map.h
@@ -32,20 +32,22 @@ class ProviderInterface;
 
 class ContentSettingsDetails;
 class DictionaryValue;
+class ExtensionService;
 class GURL;
 class PrefService;
 class Profile;
 
 class HostContentSettingsMap
     : public NotificationObserver,
-      public base::RefCountedThreadSafe<HostContentSettingsMap,
-                                        BrowserThread::DeleteOnUIThread> {
+      public base::RefCountedThreadSafe<HostContentSettingsMap> {
  public:
   typedef Tuple3<ContentSettingsPattern, ContentSetting, std::string>
       PatternSettingSourceTriple;
   typedef std::vector<PatternSettingSourceTriple> SettingsForOneType;
 
-  explicit HostContentSettingsMap(Profile* profile);
+  HostContentSettingsMap(PrefService* prefs,
+                         ExtensionService* extension_service,
+                         bool incognito);
 
   static void RegisterUserPrefs(PrefService* prefs);
 
@@ -194,8 +196,7 @@ class HostContentSettingsMap
                        const NotificationDetails& details);
 
  private:
-  friend struct BrowserThread::DeleteOnThread<BrowserThread::UI>;
-  friend class DeleteTask<HostContentSettingsMap>;
+  friend class base::RefCountedThreadSafe<HostContentSettingsMap>;
 
   virtual ~HostContentSettingsMap();
 
@@ -205,16 +206,13 @@ class HostContentSettingsMap
       ContentSettingsType content_type,
       const std::string& resource_identifier) const;
 
-  void UnregisterObservers();
-
   // Various migration methods (old cookie, popup and per-host data gets
   // migrated to the new format).
-  void MigrateObsoleteCookiePref(PrefService* prefs);
+  void MigrateObsoleteCookiePref();
 
-  // The profile we're associated with.
-  Profile* profile_;
+  // Weak; owned by the Profile.
+  PrefService* prefs_;
 
-  NotificationRegistrar notification_registrar_;
   PrefChangeRegistrar pref_change_registrar_;
 
   // Whether this settings map is for an OTR session.
diff --git a/chrome/browser/content_settings/host_content_settings_map_unittest.cc b/chrome/browser/content_settings/host_content_settings_map_unittest.cc
index 4563cbb..5490638 100644
--- a/chrome/browser/content_settings/host_content_settings_map_unittest.cc
+++ b/chrome/browser/content_settings/host_content_settings_map_unittest.cc
@@ -617,10 +617,10 @@ TEST_F(HostContentSettingsMapTest, OffTheRecord) {
   TestingProfile profile;
   HostContentSettingsMap* host_content_settings_map =
       profile.GetHostContentSettingsMap();
-  profile.set_incognito(true);
   scoped_refptr<HostContentSettingsMap> otr_map(
-      new HostContentSettingsMap(&profile));
-  profile.set_incognito(false);
+      new HostContentSettingsMap(profile.GetPrefs(),
+                                 profile.GetExtensionService(),
+                                 true));
 
   GURL host("http://example.com/");
   ContentSettingsPattern pattern =
@@ -660,6 +660,8 @@ TEST_F(HostContentSettingsMapTest, OffTheRecord) {
   EXPECT_EQ(CONTENT_SETTING_ALLOW,
             otr_map->GetContentSetting(
                 host, host, CONTENT_SETTINGS_TYPE_IMAGES, ""));
+
+  otr_map->ShutdownOnUIThread();
 }
 
 TEST_F(HostContentSettingsMapTest, MigrateObsoletePrefs) {
diff --git a/chrome/browser/profiles/profile.cc b/chrome/browser/profiles/profile.cc
index 2e23117..ab8534d 100644
--- a/chrome/browser/profiles/profile.cc
+++ b/chrome/browser/profiles/profile.cc
@@ -517,8 +517,10 @@ class OffTheRecordProfileImpl : public Profile,
     // Retrieve the host content settings map of the parent profile in order to
     // ensure the preferences have been migrated.
     profile_->GetHostContentSettingsMap();
-    if (!host_content_settings_map_.get())
-      host_content_settings_map_ = new HostContentSettingsMap(this);
+    if (!host_content_settings_map_.get()) {
+      host_content_settings_map_ = new HostContentSettingsMap(
+          GetPrefs(), GetExtensionService(), true);
+    }
     return host_content_settings_map_.get();
   }
 
diff --git a/chrome/browser/profiles/profile_impl.cc b/chrome/browser/profiles/profile_impl.cc
index b6bef63..619ff13 100644
--- a/chrome/browser/profiles/profile_impl.cc
+++ b/chrome/browser/profiles/profile_impl.cc
@@ -947,8 +947,10 @@ net::SSLConfigService* ProfileImpl::GetSSLConfigService() {
 }
 
 HostContentSettingsMap* ProfileImpl::GetHostContentSettingsMap() {
-  if (!host_content_settings_map_.get())
-    host_content_settings_map_ = new HostContentSettingsMap(this);
+  if (!host_content_settings_map_.get()) {
+    host_content_settings_map_ = new HostContentSettingsMap(
+        GetPrefs(), GetExtensionService(), false);
+  }
   return host_content_settings_map_.get();
 }
 
diff --git a/chrome/test/testing_profile.cc b/chrome/test/testing_profile.cc
index 2738406..ec65b2b 100644
--- a/chrome/test/testing_profile.cc
+++ b/chrome/test/testing_profile.cc
@@ -175,14 +175,14 @@ TestingProfile::~TestingProfile() {
 
   profile_dependency_manager_->DestroyProfileServices(this);
 
+  if (host_content_settings_map_)
+    host_content_settings_map_->ShutdownOnUIThread();
+
   DestroyTopSites();
   DestroyHistoryService();
   // FaviconService depends on HistoryServce so destroying it later.
   DestroyFaviconService();
   DestroyWebDataService();
-  if (extension_service_.get()) {
-    extension_service_.reset();
-  }
 
   if (pref_proxy_config_tracker_.get())
     pref_proxy_config_tracker_->DetachFromPrefService();
@@ -611,8 +611,10 @@ FindBarState* TestingProfile::GetFindBarState() {
 }
 
 HostContentSettingsMap* TestingProfile::GetHostContentSettingsMap() {
-  if (!host_content_settings_map_.get())
-    host_content_settings_map_ = new HostContentSettingsMap(this);
+  if (!host_content_settings_map_.get()) {
+    host_content_settings_map_ = new HostContentSettingsMap(
+        GetPrefs(), GetExtensionService(), false);
+  }
   return host_content_settings_map_.get();
 }
 
diff --git a/tools/valgrind/memcheck/suppressions.txt b/tools/valgrind/memcheck/suppressions.txt
index 7b39526..3920dda 100644
--- a/tools/valgrind/memcheck/suppressions.txt
+++ b/tools/valgrind/memcheck/suppressions.txt
@@ -3328,23 +3328,6 @@
    fun:_ZN14ProfileManager10AddProfileEP7Profileb
 }
 {
-   bug_66853_b
-   Memcheck:Leak
-   fun:_Znw*
-   fun:_ZN11ProfileImpl25GetHostContentSettingsMapEv
-   ...
-   fun:_ZNK17ProfileImplIOData6Handle27GetMainRequestContextGetterEv
-   fun:_ZN11ProfileImpl17GetRequestContextEv
-   fun:_ZN19SafeBrowsingService5StartEv
-   fun:_ZN19SafeBrowsingService10InitializeEv
-   fun:_ZN22ResourceDispatcherHost10InitializeEv
-   fun:_ZN18BrowserProcessImpl28CreateResourceDispatcherHostEv
-   fun:_ZN18BrowserProcessImpl24resource_dispatcher_hostEv
-   fun:_ZN16ExtensionService4InitEv
-   fun:_ZN11ProfileImpl14InitExtensionsE*
-   fun:_ZN14ProfileManager10AddProfileEP7Profileb
-}
-{
    bug_67142
    Memcheck:Leak
    fun:_Znw*
@@ -4804,22 +4787,6 @@
 }
 
 {
-  bug_88557
-  Memcheck:Leak
-  fun:_Znw*
-  fun:_ZN14ExtensionPrefsC1EP11PrefServiceRK8FilePathP21ExtensionPrefValueMap
-  fun:_ZN11ProfileImpl13OnPrefsLoadedEb
-  fun:_ZN11ProfileImplC1ERK8FilePathPN7Profile8DelegateE
-  fun:_ZN7Profile13CreateProfileERK8FilePath
-  fun:_ZN14ProfileManager10GetProfileERK8FilePath
-  fun:_ZN14ProfileManager17GetDefaultProfileERK8FilePath
-  fun:_ZN12_GLOBAL__N_113CreateProfileERK18MainFunctionParamsRK8FilePath
-  fun:_Z11BrowserMainRK18MainFunctionParams
-  fun:_ZN12_GLOBAL__N_123RunNamedProcessTypeMainERKSsRK18MainFunctionParams
-  fun:ChromeMain
-  fun:main
-}
-{
    bug_88735
    Memcheck:Leak
    fun:_Znw*