service worker: Fix inconsistencies in fetch timing histograms

In https://crrev.com/c/1350433 I updated some histograms for fetch
resource timing. The intention was to change the upper limit of these
histogram from 10 secs to 3 mins but I wrongly updated histograms.xml.
Specifically I should have updated histograms.xml like:
- MainResource.ForwardServiceWorkerToWorkerReady
  -> MainResource.ForwardServiceWorkerToWorkerReady2
- Subresource.ResponseReceivedToCompleted
  -> Subresource.ResponseReceivedToCompleted2

But what I did was:
- MainResource.ResponseReceivedToCompleted
  -> MainResource.ResponseReceivedToCompleted2
- Subresource.ForwardServiceWorkerToWorkerReady
  -> Subresource.ForwardServiceWorkerToWorkerReady2

This CL fixes the inconsistencies. As for ResponseReceivedToCompleted,
it would be better to use 3 mins upper limit so I added it for main
resource.

Bug: 877972
Change-Id: Ic28b5c523de7f4c150ca9cd79bf183ff37e2667d
Reviewed-on: https://chromium-review.googlesource.com/c/1364931
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614565}
3 files changed