Register a fake Flash with chrome://plugins during browser start-up.
This enables websites to query for the presence of Flash using
navigator.plugins and navigator.mimeTypes even when we don't actually
have it.

TEST=https://docs.google.com/a/google.com/document/d/1P0WslUXMUO9azLmWZ0AtQ-sGExWbHttr_2gQWDXf3MY/pub
BUG=641448,641884,641657

Review-Url: https://codereview.chromium.org/2284053002
Cr-Commit-Position: refs/heads/master@{#415100}
4 files changed