Revert "Support for measuring page load times."

The page load time measurement was a stop gap measure until server side
support is ready, and we don't want to ship with it in.

Bug: 5266893

This reverts commit b4e831bf1ff62945199b89a77ad039be7bd16545.

Change-Id: Iafc08cea88774e5ecf018112a25e4dc2993a4623
4 files changed