GitLab

When a LabelButton changes its label from a longer to a shorter string
it would not decrease in size. This patch removes that code and cleans
up the tests and related code.

Bug: 790808
Change-Id: I6fce4b3ecf3335c2a9d31bc2a3ac73e18f1e92a8
Reviewed-on: https://chromium-review.googlesource.com/798323
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521021}