Adds an experimental search/go button to the omnibox on Mac.

BUG=304859, 311269

Review URL: https://codereview.chromium.org/67513005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236388 0039d316-1c4b-4281-b951-d872f2087c98
Have ScratchBuffer::Allocate prefer allocating on the stack even if a previous
allocation required the heap.

Review URL: https://codereview.chromium.org/76943002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236389 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236388
Make animating the second notification in the message center work.

This regressed in r234064.

BUG=321771,312890

Review URL: https://codereview.chromium.org/77043008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236390 0039d316-1c4b-4281-b951-d872f2087c98
Remove obsolete code in ForeignSessionHelper.

Now that we've upgraded to the fancy new code path that enables opening
foreign sessions in the current tab, we can remove the old code.

BUG=257102
NOTRY=true

Review URL: https://codereview.chromium.org/77093002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236391 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236390
SVN changes up to revision 236391