The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f35d6bba481c47e65fd17a679a8ce1e0e419d473

commit f35d6bba481c47e65fd17a679a8ce1e0e419d473
Author: Mark Cogan <marq@google.com>
Date: Fri Aug 31 09:16:33 2018

[iOS] Add page change interaction metrics to tab grid.

This CL adds a histogram to track which of three possible interactions were used to change the current page in the tab grid.

Bug:  879487 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I35d6cb289b4c9fb8418e8d40f356bf914ae5d302
Reviewed-on: https://chromium-review.googlesource.com/1193948
Commit-Queue: Mark Cogan <marq@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587974}
[modify] https://crrev.com/f35d6bba481c47e65fd17a679a8ce1e0e419d473/ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm
[modify] https://crrev.com/f35d6bba481c47e65fd17a679a8ce1e0e419d473/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/f35d6bba481c47e65fd17a679a8ce1e0e419d473/tools/metrics/histograms/histograms.xml

Your change meets the bar and is auto-approved for M70. Please go ahead and merge the CL to branch 3538 manually. Please contact milestone owner if you have questions.
Owners: benmason@(Android), kariahda@(iOS), geohsu@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/513c8ff7ee312a0ea36a745774e0657746578f6f

commit 513c8ff7ee312a0ea36a745774e0657746578f6f
Author: Mark Cogan <marq@google.com>
Date: Mon Sep 03 10:48:58 2018

[iOS] Add page change interaction metrics to tab grid.

This CL adds a histogram to track which of three possible interactions were used to change the current page in the tab grid.

Bug:  879487 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-cronet;luci.chromium.try:ios-simulator-full-configs
Change-Id: I35d6cb289b4c9fb8418e8d40f356bf914ae5d302
Reviewed-on: https://chromium-review.googlesource.com/1193948
Commit-Queue: Mark Cogan <marq@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#587974}(cherry picked from commit f35d6bba481c47e65fd17a679a8ce1e0e419d473)
Reviewed-on: https://chromium-review.googlesource.com/1201858
Reviewed-by: Mark Cogan <marq@chromium.org>
Cr-Commit-Position: refs/branch-heads/3538@{#12}
Cr-Branched-From: 79f7c91a2b2a2932cd447fa6f865cb6662fa8fa6-refs/heads/master@{#587811}
[modify] https://crrev.com/513c8ff7ee312a0ea36a745774e0657746578f6f/ios/chrome/browser/ui/tab_grid/tab_grid_view_controller.mm
[modify] https://crrev.com/513c8ff7ee312a0ea36a745774e0657746578f6f/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/513c8ff7ee312a0ea36a745774e0657746578f6f/tools/metrics/histograms/histograms.xml