Add MOAR metrics!

[ebidel]

The perf bookmarklet at https://gist.github.com/ebidel/57c9e9379ec6b0bda16d has some numbers that would be interesting to add:

• first paint
• page load
• resource timing api load times for the page's top level html imports.
• instance count
• properties that are set to reflectToAttribute and the element that the property belongs to (can be a source of bad perf)
• WebComponentsReady firing time
• HTMLImportsLoaded firing time

[justinfagnani]

Instance count is there in there count column. It's the total instance count since page load, not just the current in-document count.

For import load times, does a top-level import's load time include it's transitive import's load times?

[ebidel]

It's hard to say because of https://code.google.com/p/chromium/issues/detail?id=505279.