Correctly integrate StoragePartition into TestingProfile.

ash/desktop_background/desktop_background_controller_unittest.cc

Index: ash/desktop_background/desktop_background_controller_unittest.cc
diff --git a/ash/desktop_background/desktop_background_controller_unittest.cc b/ash/desktop_background/desktop_background_controller_unittest.cc
index 4eb9b576d93a51ad937f4558eae838c518c48737..b46b6e336efb206fde0315d6cef32977a5c02e7f 100644
--- a/ash/desktop_background/desktop_background_controller_unittest.cc
+++ b/ash/desktop_background/desktop_background_controller_unittest.cc
@@ -100,8 +100,7 @@ void RunAnimationForWidget(views::Widget* widget) {
 class DesktopBackgroundControllerTest : public test::AshTestBase {
  public:
   DesktopBackgroundControllerTest()
-      : ui_thread_(content::BrowserThread::UI, base::MessageLoop::current()),
-        command_line_(CommandLine::NO_PROGRAM),
+      : command_line_(CommandLine::NO_PROGRAM),
         controller_(NULL) {
   }
   virtual ~DesktopBackgroundControllerTest() {}
@@ -247,8 +246,6 @@ class DesktopBackgroundControllerTest : public test::AshTestBase {
     controller_->set_command_line_for_testing(&command_line_);
   }
 
-  content::TestBrowserThread ui_thread_;
-
   // Custom command line passed to DesktopBackgroundController by
   // WriteWallpapersAndSetFlags().
   CommandLine command_line_;