GN: Make Linux build work again.

BUG=
TBR=scottmg

Review URL: https://codereview.chromium.org/24316005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224753 0039d316-1c4b-4281-b951-d872f2087c98
Fix zoom bubble issues

This CL fixes two issues with the zoom bubble:
  - tracking area wasn't working because the bubble was no longer key.
    Fix was not to use NSTrackingActiveInKeyWindow
  - zoom icon wasn't be hidden. Fix was to update decorations after
    calling SetVisible(false).

BUG=284995
TEST=Zoomed into a page. Moved the mouse over the zoom bubble. Verified
that it didn't close. Pressed reset and let the bubble close. Verified
that the zoom icon was hidden.

Review URL: https://chromiumcodereview.appspot.com/23620063

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224754 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224754