Revert "Allow CSP checkNonce and checkHash to pass with 'unsafe-inline' only."

This turns out to be the wrong way to solve the problem. We'll have to
think harder about the best way to support this (uncommon) use case.

BUG=429244
TBR=jww@chromium.org

Review URL: https://codereview.chromium.org/704723003

git-svn-id: svn://svn.chromium.org/blink/trunk@184870 bbb929c8-8fbe-4397-9dbb-9b2b20218538