WinAura: don't create tooltip on hide

The tooltip code is executed via timers from
TooltipController::UpdateIfRequired()

Which say a browser startup with no user intervention creates the tooltip
window only for the purposes of hiding it.

This fires in Ash on Windows creating a tooltip window in the wrong
side, it is hidden but it is something we want to avoid.

BUG=none
TBR=sadrul

Review URL: https://codereview.chromium.org/103143005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241139 0039d316-1c4b-4281-b951-d872f2087c98
Fix a CSS to hide the cancel button for non-cancelable progress items.

This CL fixes a CSS selector of the progress center to hide the cancel button for non-cancelable progress items.

BUG=none
TEST=manually

Review URL: https://codereview.chromium.org/105433004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241140 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241140