Add ability to retrieve capabilities for audio input devices to MediaDevicesDispatcherHost.

content/browser/renderer_host/media/media_devices_dispatcher_host.h

Index: content/browser/renderer_host/media/media_devices_dispatcher_host.h
diff --git a/content/browser/renderer_host/media/media_devices_dispatcher_host.h b/content/browser/renderer_host/media/media_devices_dispatcher_host.h
index fd06fed511d7f8670c86e7007241cbc61d31e352..ed7654cea13c784a539f6ea800c238d75f7c62cd 100644
--- a/content/browser/renderer_host/media/media_devices_dispatcher_host.h
+++ b/content/browser/renderer_host/media/media_devices_dispatcher_host.h
@@ -56,6 +56,9 @@ class CONTENT_EXPORT MediaDevicesDispatcherHost
   void GetVideoInputCapabilities(
       const url::Origin& security_origin,
       GetVideoInputCapabilitiesCallback client_callback) override;
+  void GetAudioInputCapabilities(
+      const url::Origin& security_origin,
+      GetAudioInputCapabilitiesCallback client_callback) override;
   void SubscribeDeviceChangeNotifications(
       MediaDeviceType type,
       uint32_t subscription_id,
@@ -98,6 +101,18 @@ class CONTENT_EXPORT MediaDevicesDispatcherHost
       const std::string& default_device_id,
       const media::VideoCaptureDeviceDescriptors& device_descriptors);
 
+  void GotDefaultAudioInputDeviceID(const url::Origin& security_origin,
+                                    const std::string& default_device_id);
+
+  void GotAudioInputEnumeration(const url::Origin& security_origin,
+                                const std::string& default_device_id,
+                                const MediaDeviceEnumeration& enumeration);
+
+  void GotAudioInputParameters(size_t index,
+                               const media::AudioParameters& parameters);
+
+  void FinalizeGetAudioInputCapabilities();
+
   // Returns the currently supported video formats for the given |device_id|.
   media::VideoCaptureFormats GetVideoInputFormats(const std::string& device_id);
 
@@ -122,6 +137,13 @@ class CONTENT_EXPORT MediaDevicesDispatcherHost
   // This field can only be accessed on the UI thread.
   ::mojom::MediaDevicesListenerPtr device_change_listener_;
 
+  // Queued requests for audio-input capabilities.
+  std::vector<GetAudioInputCapabilitiesCallback>
+      pending_audio_input_capabilities_callbacks_;
+  size_t num_pending_audio_input_parameters_;
+  std::vector<::mojom::AudioInputDeviceCapabilities>
+      current_audio_input_capabilities_;
+
   base::WeakPtrFactory<MediaDevicesDispatcherHost> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaDevicesDispatcherHost);