The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c731d6fc37247501c5160708a7e736db7559c431

commit c731d6fc37247501c5160708a7e736db7559c431
Author: Tanja Gornak <melandory@chromium.org>
Date: Fri Nov 16 14:24:51 2018

Add UMA metrics for E2E sync latency

UMA metrics that represent the total E2E latency in the life of a sync change.

Per committed sync entity, the elapsed time between the local model being changed
(e.g. password created) to the corresponding (reflection)
updates processed by the datatype model on the same device
(we’ll disable reflection-blocking).


Bug: 902343
Change-Id: Iaec9824016662d2ee984419824bde05ea99a32d4
Reviewed-on: https://chromium-review.googlesource.com/c/1292567
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Tatiana Gornak <melandory@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608764}
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/browser_sync/profile_sync_service.cc
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/base/sync_base_switches.cc
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/base/sync_base_switches.h
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/engine/non_blocking_sync_common.h
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/engine_impl/non_blocking_type_commit_contribution.cc
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/model_impl/client_tag_based_model_type_processor.cc
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/model_impl/processor_entity_tracker.cc
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/components/sync/model_impl/processor_entity_tracker.h
[modify] https://crrev.com/c731d6fc37247501c5160708a7e736db7559c431/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/970b4e3fd0906a4f69b0e9c8c846b35f2bb5c088

commit 970b4e3fd0906a4f69b0e9c8c846b35f2bb5c088
Author: Mikel Astiz <mastiz@chromium.org>
Date: Mon Dec 10 20:45:35 2018

Fix missing affected histogram suffix for Sync.E2ELatency

Follow-up to https://chromium-review.googlesource.com/c/1292567 where
the metric was instrumented, and where the relation between the new
histogram and the suffix was forgotten.

Bug: 902343
Change-Id: I1a9de66f522ebcdc70ded3cb3449e1b1783a6a98
Reviewed-on: https://chromium-review.googlesource.com/c/1370165
Reviewed-by: Tatiana Gornak <melandory@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615241}
[modify] https://crrev.com/970b4e3fd0906a4f69b0e9c8c846b35f2bb5c088/tools/metrics/histograms/histograms.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f638a1ea2d17c61303bf46706f3f5a1926ffa6b4

commit f638a1ea2d17c61303bf46706f3f5a1926ffa6b4
Author: Mikel Astiz <mastiz@chromium.org>
Date: Mon Jan 14 22:18:42 2019

Add UMA for sync server round trip latency

This should allow investigate future issues and also better understand
the headroom for improving latency of certain features.

Bug: 921026,902343
Change-Id: I05366ce4c08f102f47965bcbd4beb67d28352642
Reviewed-on: https://chromium-review.googlesource.com/c/1407085
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622628}
[modify] https://crrev.com/f638a1ea2d17c61303bf46706f3f5a1926ffa6b4/components/sync/engine_impl/syncer_proto_util.cc
[modify] https://crrev.com/f638a1ea2d17c61303bf46706f3f5a1926ffa6b4/tools/metrics/histograms/histograms.xml