Adding `content_security_policy` to the "Mappy" sample.

This involved pretty much rewriting the popup code to avoid a script injected
via `document.write` in the Maps API code.

BUG=92644
TEST=

Review URL: http://codereview.chromium.org/8311007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106043 0039d316-1c4b-4281-b951-d872f2087c98
10 files changed