Remove content::NotificationObserver dependency from most Prefs code.

Instead of using content::NotificationObserver, introduce specific
type-safe observer classes and update users to use them.  In a very
large number of cases this was the users' only reason for being a
content::NotificationObserver and they would have a lot of
boiler-plate code such as a DCHECK on the notification type and
unpacking of the generic NotificationDetails types, so this change
removes a bunch of boilerplate and introduces more type safety.

This is part of enabling more of the Prefs code to live in
base/prefs/.

TBR=ben@chromium.org,brettw@chromium.org
BUG=155525


Review URL: https://chromiumcodereview.appspot.com/11345008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@165414 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 45 insertions, 72 deletions

diff --git a/chrome/browser/content_settings/content_settings_default_provider.cc b/chrome/browser/content_settings/content_settings_default_provider.cc
index 97e6b55..ca56f7a 100644
--- a/chrome/browser/content_settings/content_settings_default_provider.cc
+++ b/chrome/browser/content_settings/content_settings_default_provider.cc
@@ -276,17 +276,13 @@ void DefaultProvider::ShutdownOnUIThread() {
   prefs_ = NULL;
 }
 
-void DefaultProvider::Observe(int type,
-                              const content::NotificationSource& source,
-                              const content::NotificationDetails& details) {
+void DefaultProvider::OnPreferenceChanged(PrefServiceBase* service,
+                                          const std::string& name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(chrome::NOTIFICATION_PREF_CHANGED, type);
-  DCHECK_EQ(content::Source<PrefService>(source).ptr(), prefs_);
-
+  DCHECK_EQ(prefs_, service);
   if (updating_preferences_)
     return;
 
-  const std::string& name = *content::Details<std::string>(details).ptr();
   if (name == prefs::kDefaultContentSettings) {
     ReadDefaultSettings(true);
   } else if (name == prefs::kGeolocationDefaultContentSetting) {
diff --git a/chrome/browser/content_settings/content_settings_default_provider.h b/chrome/browser/content_settings/content_settings_default_provider.h
index 2e5d96a..9235293 100644
--- a/chrome/browser/content_settings/content_settings_default_provider.h
+++ b/chrome/browser/content_settings/content_settings_default_provider.h
@@ -12,10 +12,9 @@
 #include "base/basictypes.h"
 #include "base/memory/linked_ptr.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/content_settings_observable_provider.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 
 class PrefService;
 
@@ -25,7 +24,7 @@ namespace content_settings {
 // user prefs. If no default values are set by the user we use the hard coded
 // default values.
 class DefaultProvider : public ObservableProvider,
-                        public content::NotificationObserver {
+                        public PrefObserver {
  public:
   static void RegisterUserPrefs(PrefService* prefs);
 
@@ -51,10 +50,9 @@ class DefaultProvider : public ObservableProvider,
 
   virtual void ShutdownOnUIThread() OVERRIDE;
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
  private:
   // Sets the fields of |settings| based on the values in |dictionary|.
diff --git a/chrome/browser/content_settings/content_settings_policy_provider.cc b/chrome/browser/content_settings/content_settings_policy_provider.cc
index cb24bfd..0160b51 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider.cc
+++ b/chrome/browser/content_settings/content_settings_policy_provider.cc
@@ -422,14 +422,11 @@ void PolicyProvider::ShutdownOnUIThread() {
   prefs_ = NULL;
 }
 
-void PolicyProvider::Observe(int type,
-                             const content::NotificationSource& source,
-                             const content::NotificationDetails& details) {
+void PolicyProvider::OnPreferenceChanged(PrefServiceBase* service,
+                                         const std::string& name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(chrome::NOTIFICATION_PREF_CHANGED, type);
-  DCHECK_EQ(content::Source<PrefService>(source).ptr(), prefs_);
+  DCHECK_EQ(prefs_, service);
 
-  const std::string& name = *content::Details<std::string>(details).ptr();
   if (name == prefs::kManagedDefaultCookiesSetting) {
     UpdateManagedDefaultSetting(CONTENT_SETTINGS_TYPE_COOKIES);
   } else if (name == prefs::kManagedDefaultImagesSetting) {
@@ -462,10 +459,8 @@ void PolicyProvider::Observe(int type,
              name == prefs::kManagedNotificationsBlockedForUrls) {
     ReadManagedContentSettings(true);
     ReadManagedDefaultSettings();
-  } else {
-    NOTREACHED();
-    return;
   }
+
   NotifyObservers(ContentSettingsPattern(),
                   ContentSettingsPattern(),
                   CONTENT_SETTINGS_TYPE_DEFAULT,
diff --git a/chrome/browser/content_settings/content_settings_policy_provider.h b/chrome/browser/content_settings/content_settings_policy_provider.h
index 586a4d40..096c09b 100644
--- a/chrome/browser/content_settings/content_settings_policy_provider.h
+++ b/chrome/browser/content_settings/content_settings_policy_provider.h
@@ -11,10 +11,10 @@
 
 #include "base/basictypes.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/content_settings_observable_provider.h"
 #include "chrome/browser/content_settings/content_settings_origin_identifier_value_map.h"
-#include "content/public/browser/notification_observer.h"
 
 class PrefService;
 
@@ -22,7 +22,7 @@ namespace content_settings {
 
 // PolicyProvider that provides managed content-settings.
 class PolicyProvider : public ObservableProvider,
-                       public content::NotificationObserver {
+                       public PrefObserver {
  public:
   explicit PolicyProvider(PrefService* prefs);
   virtual ~PolicyProvider();
@@ -46,10 +46,10 @@ class PolicyProvider : public ObservableProvider,
 
   virtual void ShutdownOnUIThread() OVERRIDE;
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
+
  private:
   // Reads the policy managed default settings.
   void ReadManagedDefaultSettings();
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.cc b/chrome/browser/content_settings/content_settings_pref_provider.cc
index 8b4887e..e5ad337 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider.cc
@@ -217,15 +217,11 @@ void PrefProvider::ClearAllContentSettingsRules(
                   std::string());
 }
 
-void PrefProvider::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
+void PrefProvider::OnPreferenceChanged(PrefServiceBase* service,
+                                       const std::string& name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(chrome::NOTIFICATION_PREF_CHANGED, type);
-  DCHECK_EQ(content::Source<PrefService>(source).ptr(), prefs_);
-  DCHECK_EQ(std::string(prefs::kContentSettingsPatternPairs),
-            *content::Details<std::string>(details).ptr());
+  DCHECK_EQ(prefs_, service);
+  DCHECK_EQ(std::string(prefs::kContentSettingsPatternPairs), name);
 
   if (updating_preferences_)
     return;
diff --git a/chrome/browser/content_settings/content_settings_pref_provider.h b/chrome/browser/content_settings/content_settings_pref_provider.h
index 9595de7..1efc5ccb 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider.h
+++ b/chrome/browser/content_settings/content_settings_pref_provider.h
@@ -11,12 +11,11 @@
 
 #include "base/basictypes.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/content_settings_observable_provider.h"
 #include "chrome/browser/content_settings/content_settings_origin_identifier_value_map.h"
 #include "chrome/browser/content_settings/content_settings_utils.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
 
 class PrefService;
 
@@ -29,7 +28,7 @@ namespace content_settings {
 // Content settings provider that provides content settings from the user
 // preference.
 class PrefProvider : public ObservableProvider,
-                     public content::NotificationObserver {
+                     public PrefObserver {
  public:
   static void RegisterUserPrefs(PrefService* prefs);
 
@@ -55,10 +54,9 @@ class PrefProvider : public ObservableProvider,
 
   virtual void ShutdownOnUIThread() OVERRIDE;
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
  private:
   friend class DeadlockCheckerThread;  // For testing.
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 3d9de68..c61b4a5 100644
--- a/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
+++ b/chrome/browser/content_settings/content_settings_pref_provider_unittest.cc
@@ -11,6 +11,7 @@
 #include "base/prefs/default_pref_store.h"
 #include "base/prefs/overlay_user_pref_store.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/prefs/testing_pref_store.h"
 #include "base/threading/platform_thread.h"
 #include "base/values.h"
@@ -20,13 +21,11 @@
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/pref_service_mock_builder.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
-#include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/testing_pref_service.h"
 #include "chrome/test/base/testing_profile.h"
-#include "content/public/browser/notification_observer.h"
 #include "content/public/test/test_browser_thread.h"
 #include "googleurl/src/gurl.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -54,7 +53,7 @@ class DeadlockCheckerThread : public base::PlatformThread::Delegate {
 
 // A helper for observing an preference changes and testing whether
 // |PrefProvider| holds a lock when the preferences change.
-class DeadlockCheckerObserver : public content::NotificationObserver {
+class DeadlockCheckerObserver : public PrefObserver {
  public:
   // |DeadlockCheckerObserver| doesn't take the ownership of |prefs| or
   // ||provider|.
@@ -66,12 +65,10 @@ class DeadlockCheckerObserver : public content::NotificationObserver {
   }
   virtual ~DeadlockCheckerObserver() {}
 
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) {
-    ASSERT_EQ(type, chrome::NOTIFICATION_PREF_CHANGED);
-    // Check whether |provider_| holds its lock. For this, we need a separate
-    // thread.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) {
+    // Check whether |provider_| holds its lock. For this, we need a
+    // separate thread.
     DeadlockCheckerThread thread(provider_);
     base::PlatformThreadHandle handle = base::kNullThreadHandle;
     ASSERT_TRUE(base::PlatformThread::Create(0, &thread, &handle));
diff --git a/chrome/browser/content_settings/cookie_settings.cc b/chrome/browser/content_settings/cookie_settings.cc
index 9407cbc..aed029e 100644
--- a/chrome/browser/content_settings/cookie_settings.cc
+++ b/chrome/browser/content_settings/cookie_settings.cc
@@ -155,20 +155,14 @@ void CookieSettings::ResetCookieSetting(
       CONTENT_SETTING_DEFAULT);
 }
 
-void CookieSettings::Observe(int type,
-                             const content::NotificationSource& source,
-                             const content::NotificationDetails& details) {
+void CookieSettings::OnPreferenceChanged(PrefServiceBase* prefs,
+                                         const std::string& name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(chrome::NOTIFICATION_PREF_CHANGED, type);
-  DCHECK_EQ(std::string(prefs::kBlockThirdPartyCookies),
-            *content::Details<std::string>(details).ptr());
-
-  PrefService* prefs = content::Source<PrefService>(source).ptr();
-  {
-    base::AutoLock auto_lock(lock_);
-    block_third_party_cookies_ = prefs->GetBoolean(
-        prefs::kBlockThirdPartyCookies);
-  }
+  DCHECK_EQ(std::string(prefs::kBlockThirdPartyCookies), name);
+
+  base::AutoLock auto_lock(lock_);
+  block_third_party_cookies_ = prefs->GetBoolean(
+      prefs::kBlockThirdPartyCookies);
 }
 
 void CookieSettings::ShutdownOnUIThread() {
diff --git a/chrome/browser/content_settings/cookie_settings.h b/chrome/browser/content_settings/cookie_settings.h
index f1aba03..853f1df 100644
--- a/chrome/browser/content_settings/cookie_settings.h
+++ b/chrome/browser/content_settings/cookie_settings.h
@@ -11,12 +11,12 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/profiles/refcounted_profile_keyed_service.h"
 #include "chrome/browser/profiles/refcounted_profile_keyed_service_factory.h"
 #include "chrome/common/content_settings.h"
-#include "content/public/browser/notification_observer.h"
 
 class ContentSettingsPattern;
 class CookieSettingsWrapper;
@@ -29,7 +29,7 @@ class Profile;
 // thread and read on any thread. One instance per profile.
 
 class CookieSettings
-    : public content::NotificationObserver,
+    : public PrefObserver,
       public RefcountedProfileKeyedService {
  public:
   CookieSettings(
@@ -91,10 +91,9 @@ class CookieSettings
   void ResetCookieSetting(const ContentSettingsPattern& primary_pattern,
                           const ContentSettingsPattern& secondary_pattern);
 
-  // |NotificationObserver| implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // |PrefObserver| implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
   // Detaches the |CookieSettings| from all |Profile|-related objects like
   // |PrefService|. This methods needs to be called before destroying the