Bug 947053 - [B2G][Helix][Camera]The viewfinder is all black if I open the camera

- workaround path
Revert "Bug 947053 - [B2G][Helix][Camera]The viewfinder is all black if I open the camera"

This reverts commit 447fffa8cb69c4cebe5bae38a5c182fd1f270646.

Conflicts:

	apps/system/js/window_manager.js