Fix regression in views infobar button horizontal margins.
When collapsing subclasses in r236844, I wrongly assumed that GetInsets() in a
subclass constructor would return empty insets; it actually returns whatever the
base class set its insets to.
In the case of the infobar buttons, however, the override values we were
attempting to set on the vertical margins matches the default button margin
values. So the easy fix is to simply not override any margins in InfoBarView.
BUG=323083
TEST=Visit a page in a different language, check that translate infobar buttons have correct margins
R=sky@chromium.org
Review URL: https://codereview.chromium.org/
85403007
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237183 0039d316-1c4b-4281-b951-d872f2087c98