Remove ExtensionPrefs's dependency on ChromeAppSorting.

chrome/browser/extensions/chrome_app_sorting.cc

Index: chrome/browser/extensions/chrome_app_sorting.cc
diff --git a/chrome/browser/extensions/chrome_app_sorting.cc b/chrome/browser/extensions/chrome_app_sorting.cc
index fa6967ebf7291a34690e423c2438ea45127d5e7d..62e9901a3ada81f5b4e9dec515f96312e0a19003 100644
--- a/chrome/browser/extensions/chrome_app_sorting.cc
+++ b/chrome/browser/extensions/chrome_app_sorting.cc
@@ -46,8 +46,8 @@ ChromeAppSorting::AppOrdinals::~AppOrdinals() {}
 ////////////////////////////////////////////////////////////////////////////////
 // ChromeAppSorting
 
-ChromeAppSorting::ChromeAppSorting(ExtensionScopedPrefs* extension_scoped_prefs)
-    : extension_scoped_prefs_(extension_scoped_prefs),
+ChromeAppSorting::ChromeAppSorting()
+    : extension_scoped_prefs_(NULL),
       extension_sync_service_(NULL),
       default_ordinals_created_(false) {
 }
@@ -55,6 +55,10 @@ ChromeAppSorting::ChromeAppSorting(ExtensionScopedPrefs* extension_scoped_prefs)
 ChromeAppSorting::~ChromeAppSorting() {
 }
 
+void ChromeAppSorting::SetExtensionScopedPrefs(ExtensionScopedPrefs* prefs) {
+  extension_scoped_prefs_ = prefs;
+}
+
 void ChromeAppSorting::SetExtensionSyncService(
     ExtensionSyncService* extension_sync_service) {
   extension_sync_service_ = extension_sync_service;