Fix spurious visibility events when committing Instant.

This CL fixes things so that we consistently handle the Instant preview when
committing, on all platforms. On a commit, whether on the current tab or a new
tab, we'll never hide the preview.

R=sky@chromium.org
BUG=none
TEST=none; no functionality change.


Review URL: https://chromiumcodereview.appspot.com/11233076

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@164350 0039d316-1c4b-4281-b951-d872f2087c98
11 files changed