Allow retrieval of media device ID salt even after ResourceContext has gone away.

chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_browsertest.cc

 // Copyright 2013 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 "base/json/json_writer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
@@ skipping 128 matching lines @@
                      std::string* id_in_origin) {
     if (!content::BrowserThread::CurrentlyOn(content::BrowserThread::IO)) {
       content::BrowserThread::PostTask(
           content::BrowserThread::IO, FROM_HERE,
           base::Bind(&WebrtcAudioPrivateTest::GetIDInOrigin,
                      this, resource_context, origin, raw_device_id,
                      id_in_origin));
       enumeration_event_.Wait();
     } else {
       *id_in_origin = content::GetHMACForMediaDeviceID(
-          resource_context,
+          resource_context->GetMediaDeviceIDSalt(),
           origin,
           raw_device_id);
       enumeration_event_.Signal();
     }
   }
 
   // Event used to signal completion of enumeration.
   base::WaitableEvent enumeration_event_;
 
   GURL source_url_;
@@ skipping 243 matching lines @@
   ASSERT_TRUE(content::ExecuteScript(tab, "browsertestRunAllTests();"));
 
   content::TitleWatcher title_watcher(tab, base::ASCIIToUTF16("success"));
   title_watcher.AlsoWaitForTitle(base::ASCIIToUTF16("failure"));
   base::string16 result = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(base::ASCIIToUTF16("success"), result);
 }
 #endif  // defined(GOOGLE_CHROME_BUILD)
 
 }  // namespace extensions