Version: ChromeDev @ 50.0.2661.9
OS: Nexus 9 @ 5.1.1

What steps will reproduce the problem?
1. Connect a BlueTooth Keyboard to your tablet
2. Start Chrome and keep hitting "Tab" on your keyboard

What is the expected output? What do you see instead?
Expected: TabStrip and its tabs will eventually be focused
Actual: TabStrip is never focused


Please use labels and text to provide additional information.
Don't think I have permissions to add labels :(

Additional text:
Tabs are purely virtual and handled by StripLayoutManager. They don't seem to be represented by anything focusable (there's an ExploreByTouchHelper for it, but that won't help with Bluetooth Keyboards)

This issue does not seem to occur on phones, as implied by https://bugs.chromium.org/p/chromium/issues/detail?id=455007 (which was able to tap the tab switcher)