Changes

For page-load tests by default, instead of using live web pages for performance testing, Raptor uses a tool called [[https://wiki.mozilla.org/TestEngineering/Performance/Raptor/Mitmproxy Mitmproxy]]. Mitmproxy allows us to record and playback test pages via a local Firefox proxy. The Mitmproxy recordings are stored on [https://github.com/mozilla/build-tooltool tooltool] and are automatically downloaded by Raptor when they are required for a test. Raptor uses mitmproxy via the [https://searchfox.org/mozilla-central/source/testing/mozbase/mozproxy mozbase mozproxy] package.

==== Warm Page-Load ====