Chrome Version: 70.0.3518.0 (Official Build) Revision	db029ca469391af74a16f87c5844bb1e3c8a9419-refs/branch-heads/3518@{#1} (32/64-bit)
OS: Windows(7,8,8.1,10), Mac(10.12.6 , 10.13.1 , 10.13.6, 10.14) and Linux(14.04).

Test-URL: http://ncu.rcnpv.com.tw/Uploads/20131231103232738561744.pdf

What steps will reproduce the problem?
1. Launch Chrome and navigate to above URL or any PDF page.
2. Select the text and drag the mouse towards downward and observe.

Actual: PDF doesn't scroll towards downward.
Expected: PDF page should scroll toward downwards.

This is a regression issue, broken in M-69 series, below is manual regression range:

Good build: 69.0.3469.3 (Revision: 569383)
Bad build: 69.0.3472.0 (Revision: 569948)

Using the 'per-revision' script providing the bisect result:

You are probably looking for a change made after 569739 (known good), but no later than 569740 (first known bad).
CHANGELOG URL:
The script might not always return single CL as suspect as some perf builds might get missing due to failure.
  https://chromium.googlesource.com/chromium/src/+log/f3d244014691009351047bf46cb2748dad959842..94c0beb64439fec7c5e5b0d9b7d45f2bcab4dc04

Suspecting: https://chromium.googlesource.com/chromium/src/+/94c0beb64439fec7c5e5b0d9b7d45f2bcab4dc04

@kenrb: Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

NOTE: This issue is also reproducible on Beta #69.0.3497.32 and Dev #70.0.3514.0

Kindly review the attached screen-cast for reference.

Thank you.
 

Deleted: Actual behavior.mp4 1.5 MB

	Actual behavior.mp4 1.5 MB View Download

Deleted: Expected behavior.mp4 2.0 MB

	Expected behavior.mp4 2.0 MB View Download