diff --git a/layout/generic/nsImageFrame.cpp b/layout/generic/nsImageFrame.cpp
index 4f16814699c1..9441ddccfe1a 100644
--- a/layout/generic/nsImageFrame.cpp
+++ b/layout/generic/nsImageFrame.cpp
@@ -1887,6 +1887,7 @@ static const char* kIconLoadPrefs[] = {
 
 nsImageFrame::IconLoad::IconLoad()
 {
+  mHasShutdown = PR_FALSE;
   // register observers
   Preferences::AddStrongObservers(this, kIconLoadPrefs);
   GetPrefs();
@@ -1895,6 +1896,10 @@ nsImageFrame::IconLoad::IconLoad()
 void
 nsImageFrame::IconLoad::Shutdown()
 {
+  if (mHasShutdown) {
+    return;
+  }
+  mHasShutdown = PR_TRUE;
   Preferences::RemoveObservers(this, kIconLoadPrefs);
   // in case the pref service releases us later
   if (mLoadingImage) {
diff --git a/layout/generic/nsImageFrame.h b/layout/generic/nsImageFrame.h
index 75bac2b3a85e..cde8ca12cfc4 100644
--- a/layout/generic/nsImageFrame.h
+++ b/layout/generic/nsImageFrame.h
@@ -327,6 +327,10 @@ private:
     // broken image and loading image icons
   public:
     IconLoad();
+    ~IconLoad()
+    {
+      Shutdown();
+    }
 
     void Shutdown();
 
@@ -359,6 +363,7 @@ private:
     nsCOMPtr<imgIRequest> mBrokenImage;
     PRPackedBool     mPrefForceInlineAltText;
     PRPackedBool     mPrefShowPlaceholders;
+    PRPackedBool     mHasShutdown;
   };
   
 public:
diff --git a/widget/src/android/AndroidBridge.cpp b/widget/src/android/AndroidBridge.cpp
index 3d1ab067b556..0c381da11672 100644
--- a/widget/src/android/AndroidBridge.cpp
+++ b/widget/src/android/AndroidBridge.cpp
@@ -45,8 +45,8 @@
 #include "AndroidBridge.h"
 #include "nsAppShell.h"
 #include "nsOSHelperAppService.h"
-#include "nsIPrefService.h"
 #include "nsWindow.h"
+#include "mozilla/Preferences.h"
 
 #ifdef DEBUG
 #define ALOG_BRIDGE(args...) ALOG(args)
@@ -249,29 +249,26 @@ AndroidBridge::NotifyIMEEnabled(int aState, const nsAString& aTypeHint,
     args[1].l = JNI()->NewString(typeHint.get(), typeHint.Length());
     args[2].l = JNI()->NewString(actionHint.get(), actionHint.Length());
     args[3].z = false;
-    nsCOMPtr<nsIPrefBranch> prefs = 
-        do_GetService(NS_PREFSERVICE_CONTRACTID);
-    if (prefs) {
-        PRInt32 landscapeFS;
-        nsresult rv = prefs->GetIntPref(IME_FULLSCREEN_PREF, &landscapeFS);
-        if (NS_SUCCEEDED(rv)) {
-            if (landscapeFS == 1) {
-                args[3].z = true;
-            } else if (landscapeFS == -1){
-                rv = prefs->GetIntPref(IME_FULLSCREEN_THRESHOLD_PREF, 
-                                       &landscapeFS);
-                if (NS_SUCCEEDED(rv)) {
-                    // the threshold is hundreths of inches, so convert the 
-                    // threshold to pixels and multiply the height by 100
-                    if (nsWindow::GetAndroidScreenBounds().height  * 100 < 
-                        landscapeFS * Bridge()->GetDPI())
-                        args[3].z = true;
-                }
 
+    PRInt32 landscapeFS;
+    if (NS_SUCCEEDED(Preferences::GetInt(IME_FULLSCREEN_PREF, &landscapeFS))) {
+        if (landscapeFS == 1) {
+            args[3].z = true;
+        } else if (landscapeFS == -1){
+            if (NS_SUCCEEDED(
+                  Preferences::GetInt(IME_FULLSCREEN_THRESHOLD_PREF,
+                                      &landscapeFS))) {
+                // the threshold is hundreths of inches, so convert the 
+                // threshold to pixels and multiply the height by 100
+                if (nsWindow::GetAndroidScreenBounds().height  * 100 < 
+                    landscapeFS * Bridge()->GetDPI()) {
+                    args[3].z = true;
+                }
             }
+
         }
     }
-    
+
     JNI()->CallStaticVoidMethodA(sBridge->mGeckoAppShellClass,
                                  sBridge->jNotifyIMEEnabled, args);
 }
diff --git a/widget/src/android/GfxInfo.cpp b/widget/src/android/GfxInfo.cpp
index 8a0638bba856..f6385656c61b 100644
--- a/widget/src/android/GfxInfo.cpp
+++ b/widget/src/android/GfxInfo.cpp
@@ -47,7 +47,6 @@
 #include "nsExceptionHandler.h"
 #include "nsICrashReporter.h"
 #define NS_CRASHREPORTER_CONTRACTID "@mozilla.org/toolkit/crash-reporter;1"
-#include "nsIPrefService.h"
 #endif
 
 using namespace mozilla::widget;
diff --git a/widget/src/android/nsAppShell.cpp b/widget/src/android/nsAppShell.cpp
index 3334f07bb92b..7f6c3be70a10 100644
--- a/widget/src/android/nsAppShell.cpp
+++ b/widget/src/android/nsAppShell.cpp
@@ -43,18 +43,16 @@
 #include "nsIObserverService.h"
 #include "nsIAppStartup.h"
 #include "nsIGeolocationProvider.h"
-#include "nsIPrefService.h"
-#include "nsIPrefLocalizedString.h"
 
 #include "mozilla/Services.h"
 #include "mozilla/unused.h"
+#include "mozilla/Preferences.h"
 #include "prenv.h"
 
 #include "AndroidBridge.h"
 #include "nsAccelerometerSystem.h"
 #include <android/log.h>
 #include <pthread.h>
-#include "nsIPrefBranch2.h"
 #include <wchar.h>
 
 #ifdef MOZ_LOGGING
@@ -102,6 +100,14 @@ nsAppShell::NotifyNativeEvent()
     mQueueCond.Notify();
 }
 
+#define PREFNAME_MATCH_OS  "intl.locale.matchOS"
+#define PREFNAME_UA_LOCALE "general.useragent.locale"
+static const char* kObservedPrefs[] = {
+  PREFNAME_MATCH_OS,
+  PREFNAME_UA_LOCALE,
+  nsnull
+};
+
 nsresult
 nsAppShell::Init()
 {
@@ -126,36 +132,21 @@ nsAppShell::Init()
     if (!bridge)
         return rv;
 
-    nsCOMPtr<nsIPrefBranch2> branch = do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
-    NS_ENSURE_SUCCESS(rv, rv);
-    branch->AddObserver("intl.locale.matchOS", this, PR_FALSE);
-    branch->AddObserver("general.useragent.locale", this, PR_FALSE);
-
-    nsString locale;
-    PRBool match = PR_FALSE;
-    rv = branch->GetBoolPref("intl.locale.matchOS", &match);
+    Preferences::AddStrongObservers(this, kObservedPrefs);
 
+    PRBool match;
+    rv = Preferences::GetBool(PREFNAME_MATCH_OS, &match);
     NS_ENSURE_SUCCESS(rv, rv);
 
     if (match) {
         bridge->SetSelectedLocale(EmptyString());
         return NS_OK;
     }
-    nsCOMPtr<nsIPrefLocalizedString> pls;
-    rv = branch->GetComplexValue("general.useragent.locale",
-                                 NS_GET_IID(nsIPrefLocalizedString),
-                                 getter_AddRefs(pls));
-    if (NS_SUCCEEDED(rv) && pls) {
-        nsXPIDLString uval;
-        pls->ToString(getter_Copies(uval));
-        if (uval)
-            locale.Assign(uval);
-    } else {
-        nsXPIDLCString cval;
-        rv = branch->GetCharPref("general.useragent.locale",
-                                 getter_Copies(cval));
-        if (NS_SUCCEEDED(rv) && cval)
-            locale.AssignWithConversion(cval);
+
+    nsAutoString locale;
+    rv = Preferences::GetLocalizedString(PREFNAME_UA_LOCALE, &locale);
+    if (NS_FAILED(rv)) {
+        rv = Preferences::GetString(PREFNAME_UA_LOCALE, &locale);
     }
 
     bridge->SetSelectedLocale(locale);
@@ -174,40 +165,27 @@ nsAppShell::Observe(nsISupports* aSubject,
         return nsBaseAppShell::Observe(aSubject, aTopic, aData);
     } else if (!strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID) && aData && (
                    nsDependentString(aData).Equals(
-                       NS_LITERAL_STRING("general.useragent.locale")) ||
+                       NS_LITERAL_STRING(PREFNAME_UA_LOCALE)) ||
                    nsDependentString(aData).Equals(
-                       NS_LITERAL_STRING("intl.locale.matchOS"))))
-    {
+                       NS_LITERAL_STRING(PREFNAME_MATCH_OS)))) {
         AndroidBridge* bridge = AndroidBridge::Bridge();
-        nsCOMPtr<nsIPrefBranch> prefs = do_QueryInterface(aSubject);
-        if (!prefs || !bridge)
+        if (!bridge) {
             return NS_OK;
+        }
 
-        nsString locale;
-        PRBool match = PR_FALSE;
-        nsresult rv = prefs->GetBoolPref("intl.locale.matchOS", &match);
+        PRBool match;
+        nsresult rv = Preferences::GetBool(PREFNAME_MATCH_OS, &match);
         NS_ENSURE_SUCCESS(rv, rv);
 
         if (match) {
             bridge->SetSelectedLocale(EmptyString());
             return NS_OK;
         }
-        nsCOMPtr<nsIPrefLocalizedString> pls;
-        rv = prefs->GetComplexValue("general.useragent.locale",
-                                    NS_GET_IID(nsIPrefLocalizedString),
-                                    getter_AddRefs(pls));
-        if (NS_SUCCEEDED(rv) && pls) {
-            nsXPIDLString uval;
-            pls->ToString(getter_Copies(uval));
-            if (uval)
-                locale.Assign(uval);
-        }
-        else {
-            nsXPIDLCString cval;
-            rv = prefs->GetCharPref("general.useragent.locale",
-                                    getter_Copies(cval));
-            if (NS_SUCCEEDED(rv) && cval)
-                locale.AssignWithConversion(cval);
+
+        nsAutoString locale;
+        if (NS_FAILED(Preferences::GetLocalizedString(PREFNAME_UA_LOCALE,
+                                                      &locale))) {
+            locale = Preferences::GetString(PREFNAME_UA_LOCALE);
         }
 
         bridge->SetSelectedLocale(locale);
@@ -362,9 +340,10 @@ nsAppShell::ProcessNextNativeEvent(PRBool mayWait)
         // We really want to send a notification like profile-before-change,
         // but profile-before-change ends up shutting some things down instead
         // of flushing data
-        nsCOMPtr<nsIPrefService> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
-        if (prefs)
+        nsIPrefService* prefs = Preferences::GetService();
+        if (prefs) {
             prefs->SavePrefFile(nsnull);
+        }
 
         break;
     }
diff --git a/widget/src/android/nsWindow.cpp b/widget/src/android/nsWindow.cpp
index 48ad135c0a2f..f60b8417b464 100644
--- a/widget/src/android/nsWindow.cpp
+++ b/widget/src/android/nsWindow.cpp
@@ -43,6 +43,7 @@
 #include "mozilla/dom/ContentParent.h"
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/unused.h"
+#include "mozilla/Preferences.h"
 
 using mozilla::dom::ContentParent;
 using mozilla::dom::ContentChild;
@@ -52,7 +53,6 @@ using mozilla::unused;
 #include "nsIdleService.h"
 #include "nsWindow.h"
 #include "nsIObserverService.h"
-#include "nsIPrefService.h"
 
 #include "nsRenderingContext.h"
 #include "nsIDOMSimpleGestureEvent.h"
@@ -1749,14 +1749,10 @@ nsWindow::SetInputMode(const IMEContext& aContext)
     // IMEContext depending on the content.ime.strict.policy pref
     if (aContext.mStatus != nsIWidget::IME_STATUS_DISABLED && 
         aContext.mStatus != nsIWidget::IME_STATUS_PLUGIN) {
-      nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
-
-      PRBool useStrictPolicy = PR_FALSE;
-      if (NS_SUCCEEDED(prefs->GetBoolPref("content.ime.strict_policy", &useStrictPolicy))) {
-        if (useStrictPolicy && !aContext.FocusMovedByUser() && 
-            aContext.FocusMovedInContentProcess()) {
-          return NS_OK;
-        }
+      if (Preferences::GetBool("content.ime.strict_policy", PR_FALSE) &&
+          !aContext.FocusMovedByUser() &&
+          aContext.FocusMovedInContentProcess()) {
+        return NS_OK;
       }
     }
 
diff --git a/widget/src/cocoa/GfxInfo.mm b/widget/src/cocoa/GfxInfo.mm
index 83e7bbc7711d..913a6599c21c 100644
--- a/widget/src/cocoa/GfxInfo.mm
+++ b/widget/src/cocoa/GfxInfo.mm
@@ -48,7 +48,6 @@
 #include "nsExceptionHandler.h"
 #include "nsICrashReporter.h"
 #define NS_CRASHREPORTER_CONTRACTID "@mozilla.org/toolkit/crash-reporter;1"
-#include "nsIPrefService.h"
 #endif
 
 using namespace mozilla::widget;
diff --git a/widget/src/os2/nsDeviceContextSpecOS2.cpp b/widget/src/os2/nsDeviceContextSpecOS2.cpp
index 856ac94a5066..e9e17ab3b835 100644
--- a/widget/src/os2/nsDeviceContextSpecOS2.cpp
+++ b/widget/src/os2/nsDeviceContextSpecOS2.cpp
@@ -44,8 +44,6 @@
 #include "nsReadableUtils.h"
 #include "nsTArray.h"
 
-#include "nsIPrefService.h"
-#include "nsIPrefBranch.h"
 #include "prenv.h" /* for PR_GetEnv */
 #include "prtime.h"
 
@@ -64,6 +62,10 @@
 #include "gfxOS2Surface.h"
 #include "nsIPrintSettingsService.h"
 
+#include "mozilla/Preferences.h"
+
+using namespace mozilla;
+
 PRINTDLG nsDeviceContextSpecOS2::PrnDlg;
 
 //----------------------------------------------------------------------------------
@@ -657,9 +659,8 @@ nsresult GlobalPrinters::InitializeGlobalPrinters ()
   if (!mGlobalPrinterList) 
      return NS_ERROR_OUT_OF_MEMORY;
 
-  nsresult rv;
-  nsCOMPtr<nsIPrefBranch> pPrefs = do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
-  BOOL prefFailed = NS_FAILED(rv); // don't return on failure, optional feature
+  // don't return on failure, optional feature
+  BOOL prefFailed = (Preferences::GetRootBranch() != nsnull);
 
   for (ULONG i = 0; i < mGlobalNumPrinters; i++) {
     nsXPIDLCString printer;
@@ -667,8 +668,8 @@ nsresult GlobalPrinters::InitializeGlobalPrinters ()
 
     nsAutoChar16Buffer printerName;
     PRInt32 printerNameLength;
-    rv = MultiByteToWideChar(0, printer, strlen(printer),
-                             printerName, printerNameLength);
+    nsresult rv = MultiByteToWideChar(0, printer, strlen(printer),
+                                      printerName, printerNameLength);
     mGlobalPrinterList->AppendElement(nsDependentString(printerName.Elements()));
 
     // store printer description in prefs for the print dialog
@@ -678,10 +679,10 @@ nsresult GlobalPrinters::InitializeGlobalPrinters ()
        printerDescription += " (";
        printerDescription += nsCAutoString(nsDeviceContextSpecOS2::PrnDlg.GetDriverType(i));
        printerDescription += ")";
-       pPrefs->SetCharPref(nsPrintfCString(256,
-                                           "print.printer_%s.printer_description",
-                                           printer.get()).get(),
-                           printerDescription.get());
+       nsCAutoString prefName("print.printer_");
+       prefName += printer;
+       prefName += ".printer_description";
+       Preferences::SetCString(prefName.get(), printerDescription);
     }
   } 
   return NS_OK;
diff --git a/widget/src/os2/nsWindow.cpp b/widget/src/os2/nsWindow.cpp
index f78ff92b496c..74b2d83e4cc2 100644
--- a/widget/src/os2/nsWindow.cpp
+++ b/widget/src/os2/nsWindow.cpp
@@ -75,7 +75,6 @@
 #include "nsGfxCIID.h"
 #include "nsHashKeys.h"
 #include "nsIMenuRollup.h"
-#include "nsIPrefService.h"
 #include "nsIRollupListener.h"
 #include "nsIScreenManager.h"
 #include "nsOS2Uni.h"
@@ -84,6 +83,10 @@
 #include "nsWidgetAtoms.h"
 #include "wdgtos2rc.h"
 
+#include "mozilla/Preferences.h"
+
+using namespace mozilla;
+
 //=============================================================================
 //  Macros
 //=============================================================================
@@ -309,14 +312,8 @@ void nsWindow::InitGlobals()
   // it scroll messages. Needless to say, no Mozilla window has real scroll
   // bars. So if you have the "os2.trackpoint" preference set, we put an
   // invisible scroll bar on every child window so we can scroll.
-  nsresult rv;
-  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &rv));
-  if (NS_SUCCEEDED(rv) && prefs) {
-    PRBool isTrackPoint = PR_FALSE;
-    prefs->GetBoolPref("os2.trackpoint", &isTrackPoint);
-    if (isTrackPoint) {
-      gOS2Flags |= kIsTrackPoint;
-    }
+  if (Preferences::GetBool("os2.trackpoint", PR_FALSE)) {
+    gOS2Flags |= kIsTrackPoint;
   }
 }
 
diff --git a/widget/src/qt/nsDeviceContextSpecQt.cpp b/widget/src/qt/nsDeviceContextSpecQt.cpp
index d3aba4cede36..6a9605d55887 100644
--- a/widget/src/qt/nsDeviceContextSpecQt.cpp
+++ b/widget/src/qt/nsDeviceContextSpecQt.cpp
@@ -56,8 +56,6 @@
 
 #include "nsDeviceContextSpecQt.h"
 
-#include "nsIPrefService.h"
-#include "nsIPrefBranch.h"
 #include "prenv.h" /* for PR_GetEnv */
 
 #include "nsPrintfCString.h"
diff --git a/widget/src/qt/nsWindow.cpp b/widget/src/qt/nsWindow.cpp
index 5c988a6c49bd..2fb711bafeec 100644
--- a/widget/src/qt/nsWindow.cpp
+++ b/widget/src/qt/nsWindow.cpp
@@ -102,9 +102,8 @@ using namespace QtMobility;
 #include "nsWidgetsCID.h"
 #include "nsQtKeyUtils.h"
 #include "mozilla/Services.h"
+#include "mozilla/Preferences.h"
 
-#include "nsIPrefService.h"
-#include "nsIPrefBranch.h"
 #include "nsIStringBundle.h"
 #include "nsGfxCIID.h"
 
@@ -2497,15 +2496,9 @@ nsresult
 initialize_prefs(void)
 {
     // check to see if we should set our raise pref
-    nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
-    if (!prefs)
-        return NS_OK;
-
-    PRBool val = PR_TRUE;
-    nsresult rv;
-    rv = prefs->GetBoolPref("mozilla.widget.disable-native-theme", &val);
-    if (NS_SUCCEEDED(rv))
-        gDisableNativeTheme = val;
+    gDisableNativeTheme =
+        Preferences::GetBool("mozilla.widget.disable-native-theme",
+                             gDisableNativeTheme);
 
     return NS_OK;
 }
@@ -3047,11 +3040,8 @@ nsWindow::SetInputMode(const IMEContext& aContext)
         case nsIWidget::IME_STATUS_ENABLED:
         case nsIWidget::IME_STATUS_PASSWORD:
             {
-                PRInt32 openDelay = 200;
-                nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
-                if (prefs)
-                  prefs->GetIntPref("ui.vkb.open.delay", &openDelay);
-
+                PRInt32 openDelay =
+                    Preferences::GetInt("ui.vkb.open.delay", 200);
                 mWidget->requestVKB(openDelay);
             }
             break;
diff --git a/widget/src/windows/GfxInfo.cpp b/widget/src/windows/GfxInfo.cpp
index 9e91ab027116..aebb4c21ae37 100644
--- a/widget/src/windows/GfxInfo.cpp
+++ b/widget/src/windows/GfxInfo.cpp
@@ -52,7 +52,6 @@
 #include "nsExceptionHandler.h"
 #include "nsICrashReporter.h"
 #define NS_CRASHREPORTER_CONTRACTID "@mozilla.org/toolkit/crash-reporter;1"
-#include "nsIPrefService.h"
 #endif