GitLab

Currently the Virtual Keyboard is difficult to use
when the Fullscreen Magnifier is enabled

Improvements include:
- Keeping the Virtual Keyboard in the same size and
  position when Fullscreen Magnifier is enabled. This
  is done by applying the magnifier's inverse transform
  on the Virtual Keyboard's container.
- Reduce the bottom margin to pan down the magnifier so
  that you can interact with the keyboard without
  panning.

This CL disables keyboard overscroll when the fullscreen
magnifier is enabled since overscroll would cause layout
issues.

Screenshot: https://screenshot.googleplex.com/BXnT2RG4A7h

Testing: ash_unittests
  - MagnificationControllerTest.TextfieldFocusedWithKeyboard
  - MagnificationControllerTest.KeyboardOverscrollDisabled

Bug: 347252
Change-Id: Ibcdd43573b211d6bad21b60bb19f427a58490c3f
Reviewed-on: https://chromium-review.googlesource.com/1009269
Commit-Queue: Sarah Chan <spqchan@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Reviewed-by: Darren Shen <shend@chromium.org>
Reviewed-by: David Vallet <dvallet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561685}