Revert "Bug 912951 - Send content event from gaia -> chrome with layout info for supportsSwitching"

This reverts commit 6c18cc2aa298247ab218c7222a8f32f1b3e29880.
Merge pull request #12197 from comoyo/revert_supportsswitching

Revert "Bug 912951 - Send content event from gaia -> chrome with layout info for supportsSwitching"