Chrome Version       : 67.0.3384.0
OS Version: Android 8.1.0 on Pixel 2
URLs (if applicable) :
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari:
    Firefox:
    IE/Edge:

What steps will reproduce the problem?
1. Enable Microphone support for Chrome
2. Launch Permission.site
3. Request the Microphone
4. Launch a New Tab page
5. Enter VR
6. Launch a Youtube video.
7. Try to control the volume using the Daydream control while in VR

What is the expected result?
When no other tab is using the Microphone the Daydream control works correctly controlling the volume on the current page.  This is expected even if another tab is using the Microphone.

What happens instead of that?
The user is unable to control the volume on the current page using the Daydream controller.  Turning the volume up or down does nothing.