(re-land) Disallow navigations to blob URLs with non-canonical origins.

Re-landing this with a fix for xhr-to-blob-in-isolated-world.html

BUG=646278
TEST=content_browsertests, included

Review-Url: https://codereview.chromium.org/2365433002
Cr-Commit-Position: refs/heads/master@{#420436}
5 files changed