Store device salt callback instead of resource context in WebRTC Audio Private API

chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_api.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_WEBRTC_AUDIO_PRIVATE_WEBRTC_AUDIO_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_WEBRTC_AUDIO_PRIVATE_WEBRTC_AUDIO_PRIVATE_API_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/system_monitor/system_monitor.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "chrome/common/extensions/api/webrtc_audio_private.h"
 #include "content/public/browser/render_process_host.h"
+#include "content/public/browser/resource_context.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "media/audio/audio_device_name.h"
 #include "url/gurl.h"
 
-namespace content {
-class ResourceContext;
-}
-
 namespace extensions {
 
 // Listens for device changes and forwards as an extension event.
 class WebrtcAudioPrivateEventService
     : public BrowserContextKeyedAPI,
       public base::SystemMonitor::DevicesChangedObserver {
  public:
   explicit WebrtcAudioPrivateEventService(content::BrowserContext* context);
   ~WebrtcAudioPrivateEventService() override;
 
@@ skipping 53 matching lines @@
   void CalculateHMAC(const std::string& raw_id);
 
   // Must override this if you call CalculateHMAC.
   virtual void OnHMACCalculated(const std::string& hmac);
 
   // Calculates a single HMAC, using the extension ID as the security origin.
   //
   // Call only on IO thread.
   std::string CalculateHMACImpl(const std::string& raw_id);
 
-  // Initializes |resource_context_|. Must be called on the UI thread,
-  // before any calls to |resource_context()|.
-  void InitResourceContext();
+  // Initializes |device_id_salt_|. Must be called on the UI thread,
+  // before any calls to |device_id_salt()|.
+  void InitDeviceIDSalt();
 
   // Callable from any thread. Must previously have called
-  // |InitResourceContext()|.
-  content::ResourceContext* resource_context() const;
+  // |InitDeviceIDSalt()|.
+  const content::ResourceContext::SaltCallback& device_id_salt() const;
 
  private:
-  content::ResourceContext* resource_context_;
+  content::ResourceContext::SaltCallback device_id_salt_;
 
   DISALLOW_COPY_AND_ASSIGN(WebrtcAudioPrivateFunction);
 };
 
 class WebrtcAudioPrivateGetSinksFunction : public WebrtcAudioPrivateFunction {
  protected:
   ~WebrtcAudioPrivateGetSinksFunction() override {}
 
  private:
   DECLARE_EXTENSION_FUNCTION("webrtcAudioPrivate.getSinks",
@@ skipping 106 matching lines @@
   // time, no locking needed.
   scoped_ptr<api::webrtc_audio_private::GetAssociatedSink::Params> params_;
 
   // Audio sources (input devices). Filled in by DoWorkOnDeviceThread.
   media::AudioDeviceNames source_devices_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_WEBRTC_AUDIO_PRIVATE_WEBRTC_AUDIO_PRIVATE_API_H_