Fix hover effect on notification button icons.

The button was not showing the hover effect when its child views
were hovered.

BUG=314741

Review URL: https://codereview.chromium.org/64553003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233844 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233844
Use software renderer for windows with an initial size less than 64x64

If the width or height of a window is less than 64 pixels then some AMD drivers have problems presenting from them, so composite those windows in software.

BUG=286609

Review URL: https://codereview.chromium.org/59913008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233845 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233845