Add duplex flag and deprecate Chrome Home check

This patch adds a new flag for Chrome Duplex since there is too much
overhead in reusing the original Chrome Home flag. isChromeHomeEnabled
now always returns false. Tests that depend on the bottom sheet have
been removed with the exception of those related to suggestions,
observers, and swipe logic (which are temporarily disabled).

BUG=805070

Change-Id: I1ec39da11e1e7e0f14cbbe9e77a24f3cd16edd10
Reviewed-on: https://chromium-review.googlesource.com/876529
Commit-Queue: Matthew Jones <[email protected]>
Reviewed-by: Theresa <[email protected]>
Reviewed-by: Bernhard Bauer <[email protected]>
Cr-Commit-Position: refs/heads/master@{#534724}
32 files changed