Disallow CSP source * matching of data:, blob:, and filesystem: URLs

The CSP spec specifically excludes matching of data:, blob:, and
filesystem: URLs with the source '*' wildcard. This adds checks to make
sure that doesn't happen, along with tests.

BUG=534570
R=mkwst@chromium.org

Review URL: https://codereview.chromium.org/1361763005

Cr-Commit-Position: refs/heads/master@{#350950}
bool CSPSourceList::allowEval() const
{
    return m_allowEval;
}

bool CSPSourceList::allowEval() const
{
    return m_allowEval;
}
