Capture timeline should display thread names/ids, and color deterministically

[michaelkvance]

Currently the capture timeline doesn't display the thread names or ids (normally shown on the left side regardless of timeline position). Nor does it have deterministic coloring; in most profilers this is either user-configured via some mapping mechanism, or deterministically generated via a hash of the name or id.

[florian-kuebler]

PIDs and thread names should be reported by now. We internally track the deterministic coloring under http://b/168104534.

[florian-kuebler]

Closing this as colors are deterministic by thread name by now.