Remove //chrome dependency from ExtensionPrefs

chrome/browser/extensions/test_extension_prefs.cc

Index: chrome/browser/extensions/test_extension_prefs.cc
diff --git a/chrome/browser/extensions/test_extension_prefs.cc b/chrome/browser/extensions/test_extension_prefs.cc
index 276980a3c30342e31fa476333ed06f159a8fce78..79a1d53822f0e6139fcfe374e77c5b19d08d1b20 100644
--- a/chrome/browser/extensions/test_extension_prefs.cc
+++ b/chrome/browser/extensions/test_extension_prefs.cc
@@ -117,10 +117,10 @@ void TestExtensionPrefs::RecreateExtensionPrefs() {
       extension_pref_value_map_.get(),
       ExtensionsBrowserClient::Get()->CreateAppSorting().Pass(),
       extensions_disabled_,
+      std::vector<ExtensionPrefs::Observer*>(),
       // Guarantee that no two extensions get the same installation time
       // stamp and we can reliably assert the installation order in the tests.
-      scoped_ptr<ExtensionPrefs::TimeProvider>(
-          new IncrementalTimeProvider())));
+      scoped_ptr<ExtensionPrefs::TimeProvider>(new IncrementalTimeProvider())));
 }
 
 scoped_refptr<Extension> TestExtensionPrefs::AddExtension(std::string name) {