chromeos: fix bug where "aw snap" page replaces first tab if it was a NTP when closing window with > 1 tab.

BUG=chromium-os:12088
TEST=verify bug per bug report.
Review URL: http://codereview.chromium.org/6882058

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@83031 0039d316-1c4b-4281-b951-d872f2087c98
  TabContentsWrapper* CreateTabContentsWithSharedRPH(
      TabContents* tab_contents) {
    TabContentsWrapper* retval = Browser::TabContentsFactory(profile(),
        tab_contents->render_view_host()->site_instance(), MSG_ROUTING_NONE,
        NULL, NULL);
    EXPECT_EQ(retval->tab_contents()->GetRenderProcessHost(),
              tab_contents->GetRenderProcessHost());
    return retval;
  }

  TabContentsWrapper* CreateTabContentsWithSharedRPH(
      TabContents* tab_contents) {
    TabContentsWrapper* retval = Browser::TabContentsFactory(profile(),
        tab_contents->render_view_host()->site_instance(), MSG_ROUTING_NONE,
        NULL, NULL);
    EXPECT_EQ(retval->tab_contents()->GetRenderProcessHost(),
              tab_contents->GetRenderProcessHost());
    return retval;
  }
