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

ppapi/cpp/private/camera_device_private.h

Index: ppapi/cpp/private/camera_device_private.h
diff --git a/ppapi/cpp/private/camera_device_private.h b/ppapi/cpp/private/camera_device_private.h
index d6c774eeb18d3bb7b9a18e70726d9185e2dcb567..2e504a31117f3e3df5a1d2e0d7819d6b2ba02458 100644
--- a/ppapi/cpp/private/camera_device_private.h
+++ b/ppapi/cpp/private/camera_device_private.h
@@ -66,7 +66,7 @@ class CameraDevice_Private : public Resource {
   ///
   /// @param[in] device_id A <code>Var</code> identifying a camera
   /// device. The type is string. The ID can be obtained from
-  /// MediaStreamTrack.getSources() or MediaStreamVideoTrack.id.
+  /// navigator.mediaDevices.enumerateDevices() or MediaStreamVideoTrack.id.
   /// @param[in] callback A <code>CompletionCallback</code> to be called upon
   /// completion of <code>Open()</code>.
   ///