DevTools: [Timeline] extract common testing harness code from tracing tests.

BUG=

Review URL: https://codereview.chromium.org/391413003

git-svn-id: svn://svn.chromium.org/blink/trunk@178543 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add the WOFF 2.0 MIME type

Patch by Mathias Bynens <mathiasb@opera.com>;.

BUG=391289
TBR=eustas

Review URL: https://codereview.chromium.org/404053003

git-svn-id: svn://svn.chromium.org/blink/trunk@178545 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Slightly simplify building FillLayer objects

Review URL: https://codereview.chromium.org/405093002

git-svn-id: svn://svn.chromium.org/blink/trunk@178546 bbb929c8-8fbe-4397-9dbb-9b2b20218538