Replace references to MediaStreamTrack.getSources() with enumerateDevices() in PPAPI.

ppapi/api/private/ppb_camera_device_private.idl

Index: ppapi/api/private/ppb_camera_device_private.idl
diff --git a/ppapi/api/private/ppb_camera_device_private.idl b/ppapi/api/private/ppb_camera_device_private.idl
index d87ac2059a8e0d236e75996cb557294a17a2e5a6..9d3040741618bc964968f3979f7858dbf672c217 100644
--- a/ppapi/api/private/ppb_camera_device_private.idl
+++ b/ppapi/api/private/ppb_camera_device_private.idl
@@ -51,8 +51,8 @@ interface PPB_CameraDevice_Private {
    * @param[in] camera_device A <code>PP_Resource</code> corresponding to a
    * camera device resource.
    * @param[in] device_id A <code>PP_Var</code> identifying a camera device. The
-   * type is string. The ID can be obtained from MediaStreamTrack.getSources()
-   * or MediaStreamVideoTrack.id.
+   * type is string. The ID can be obtained from
+   * navigator.mediaDevices.enumerateDevices() or MediaStreamVideoTrack.id.
    * @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
    * completion of <code>Open()</code>.
    *