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

chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.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 "chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h"
 
 #include "base/lazy_instance.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task_runner_util.h"
 #include "chrome/browser/extensions/api/tabs/tabs_constants.h"
@@ skipping 168 matching lines @@
 
   // We don't hash the default device name, and we always return
   // "default" for the default device. There is code in SetActiveSink
   // that transforms "default" to the empty string, and code in
   // GetActiveSink that ensures we return "default" if we get the
   // empty string as the current device ID.
   if (raw_id.empty() || raw_id == media::AudioManagerBase::kDefaultDeviceId)
     return media::AudioManagerBase::kDefaultDeviceId;
 
   GURL security_origin(source_url().GetOrigin());
-  return content::GetHMACForMediaDeviceID(resource_context(),
-                                          security_origin,
-                                          raw_id);
+  return content::GetHMACForMediaDeviceID(
+      resource_context()->GetMediaDeviceIDSalt(),
+      security_origin,
+      raw_id);
 }
 
 void WebrtcAudioPrivateFunction::InitResourceContext() {
   resource_context_ = GetProfile()->GetResourceContext();
 }
 
 content::ResourceContext* WebrtcAudioPrivateFunction::resource_context() const {
   DCHECK(resource_context_);  // Did you forget to InitResourceContext()?
   return resource_context_;
 }
@@ skipping 219 matching lines @@
   GURL security_origin(params_->security_origin);
   std::string source_id_in_origin(params_->source_id_in_origin);
 
   // Find the raw source ID for source_id_in_origin.
   std::string raw_source_id;
   for (AudioDeviceNames::const_iterator it = source_devices_.begin();
        it != source_devices_.end();
        ++it) {
     const std::string& id = it->unique_id;
     if (content::DoesMediaDeviceIDMatchHMAC(
-            resource_context(),
+            resource_context()->GetMediaDeviceIDSalt(),
             security_origin,
             source_id_in_origin,
             id)) {
       raw_source_id = id;
       DVLOG(2) << "Found raw ID " << raw_source_id
                << " for source ID in origin " << source_id_in_origin;
       break;
     }
   }
 
@@ skipping 23 matching lines @@
 void WebrtcAudioPrivateGetAssociatedSinkFunction::OnHMACCalculated(
     const std::string& associated_sink_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   results_.reset(
       wap::GetAssociatedSink::Results::Create(associated_sink_id).release());
   SendResponse(true);
 }
 
 }  // namespace extensions