Measure and report time between user-space process crashes.

BUG=none
TEST=unit tests, gmerged on the device and inspected
logs, about:histograms,etc.

Review URL: http://codereview.chromium.org/2736008
6 files changed
tree: d612c1542516f3e5fb4f0719d52a0a904283e694
  1. metrics/