[NaCl SDK AppEngine] Add a fullscreen bullet demo.

The fullscreen view moves the controls to a panel in the upper-left, and
removes most of the text.

Also, fix some flexbox bugs that only appear in Chrome 34 (not Chrome 32). It
seems that the flex-shrink attribute needs to be 1 now, or the element will use
more than its desired size, even if flex-grow is 0. Not sure if this is a bug
or not...

BUG=341666
R=sbc@chromium.org

Review URL: https://codereview.chromium.org/140093007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251843 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251843