Only have middle click lower the window if we hit the titlebar or window edge.  Middle clicking a link on the page shouldn't do this.
Only have middle click lower the window if we hit the titlebar or
window edge.  Middle clicking a link on the page shouldn't do
this.

BUG=15430

Review URL: http://codereview.chromium.org/164257


git-svn-id: http://src.chromium.org/svn/trunk/src@22924 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 7e3208e909621a65809383735934b768bdb8f2bd
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser