Add a receiver interface to RemovableStorageNotifications.

chrome/browser/system_monitor/media_storage_util_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <string>
 
 #include "base/message_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/system_monitor/media_storage_util.h"
@@ skipping 12 matching lines @@
 const char kUniqueId[] = "VendorModelSerial:ABC:1233:1237912873";
 const char kImageCaptureDeviceId[] = "ic:xyz";
 
 }  // namespace
 
 class MediaStorageUtilTest : public testing::Test {
  public:
   void ProcessAttach(const std::string& id,
                      const string16& name,
                      const base::FilePath::StringType& location) {
-    RemovableStorageNotifications::GetInstance()->ProcessAttach(
-        id, name, location);
+    notifications_.ProcessAttach(id, name, location);
   }
 
  private:
   chrome::test::TestRemovableStorageNotifications notifications_;
 };
 
 // Test to verify |MediaStorageUtil::MakeDeviceId| functionality using a sample
 // mtp device unique id.
 TEST_F(MediaStorageUtilTest, MakeMtpDeviceId) {
   std::string device_id =
@@ skipping 49 matching lines @@
   event.Reset();
   MediaStorageUtil::FilterAttachedDevices(&devices,
       base::Bind(&base::WaitableEvent::Signal, base::Unretained(&event)));
   loop.RunUntilIdle();
   event.Wait();
 
   EXPECT_TRUE(devices.find(kImageCaptureDeviceId) != devices.end());
 }
 
 }  // namespace chrome