GitLab

 Child widget should not be parented to desktop.
 This was causing tab contents for prerendering be parented to desktop.
Fix for DCHECK failure in NativeWidgetViews::OnKeyEvent
 Child widget should not be activated.
Reset non_client_view_ when new contentview is set.

BUG=none
TEST=updated widget_unittests

Review URL: http://codereview.chromium.org/7979035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@102389 0039d316-1c4b-4281-b951-d872f2087c98