This is also an issue with touchscreen:

again from hwi@:

Google Photos carousel gesture triggers Gesture Nav, which results in page navigation.

Flickr photo panning triggers Gesture Nav, which results in page navigation.

hwi@: Can you still repro this using touchscreen on Google Photos? I used to be able to repro, but can't anymore. Probably, Photos have fixed something on their side.

mohsen@: 

- re c3, Correct, Google Photos doesn't repro with one finger pull or swipe, however, with two fingers, the pull to refresh and the swipe to back are triggered (and two finger gestures don't trigger Google Photos navigations). So the original issue is  fixed by the site. 

- the flickr issue is still the same with the one finger gesture i.e. conflicts with Flickr's prev/next nav. 

- back to Google Photos, there's a new issue on the vertical timeline scroll-scrubber where scrubbing triggers the pull-to-refresh, which makes Photos' scrubber unusable. 

See the screen recording: go/sr772106 (internal video)

Thanks for looking into it, mohsen@! 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9830436c3c1481ee9dc6e52238e40db8a22d6989

commit 9830436c3c1481ee9dc6e52238e40db8a22d6989
Author: Mohsen Izadi <mohsen@chromium.org>
Date: Thu Dec 21 22:26:39 2017

No overscroll after mouse-wheel consumed

Sometimes pages that handle mouse-wheel events to implement their own
custom scrolling/panning/zooming consume some (rather that all) of
mouse-wheel events. The mouse-wheel events that are not consumed end up
genering gesture-scroll events which might initiate overscroll
conflicting with page's own handling of mouse-wheel events. To prevent
this, as soon as a mouse-wheel event is consumed, overscroll controller
stops initiating overscroll until the user's next interaction with the
page.

This CL also inclused some cleanup to overscroll code and unit tests.

BUG=772106
TEST=OverscrollControllerTest.* in content_unittests
     RenderWidgetHostViewAuraOver*Test.* in content_unittests

Change-Id: Idc22ab44dc136dc921f75e708c247a7fcf91daa9
Reviewed-on: https://chromium-review.googlesource.com/777499
Commit-Queue: Mohsen Izadi <mohsen@chromium.org>
Reviewed-by: Sahel Sharifymoghaddam <sahel@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#525830}
[modify] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/browser/renderer_host/overscroll_controller.cc
[modify] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/browser/renderer_host/overscroll_controller.h
[add] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/browser/renderer_host/overscroll_controller_unittest.cc
[modify] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/browser/renderer_host/render_widget_host_view_aura_unittest.cc
[modify] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/test/BUILD.gn
[add] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/test/test_overscroll_delegate.cc
[add] https://crrev.com/9830436c3c1481ee9dc6e52238e40db8a22d6989/content/test/test_overscroll_delegate.h