The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1a5774e06f5d0a8794594e28a70e7c6b00106730

commit 1a5774e06f5d0a8794594e28a70e7c6b00106730
Author: yawano <yawano@chromium.org>
Date: Tue Feb 14 05:17:15 2017

Initial patch set to implement improved touch support for screen
magnification

BUG= 670526 
TEST=none

Review-Url: https://codereview.chromium.org/2641733002
Cr-Commit-Position: refs/heads/master@{#450259}

[modify] https://crrev.com/1a5774e06f5d0a8794594e28a70e7c6b00106730/ash/magnifier/magnification_controller.cc
[modify] https://crrev.com/1a5774e06f5d0a8794594e28a70e7c6b00106730/chrome/app/generated_resources.grd
[modify] https://crrev.com/1a5774e06f5d0a8794594e28a70e7c6b00106730/chrome/browser/about_flags.cc
[modify] https://crrev.com/1a5774e06f5d0a8794594e28a70e7c6b00106730/chromeos/chromeos_switches.cc
[modify] https://crrev.com/1a5774e06f5d0a8794594e28a70e7c6b00106730/chromeos/chromeos_switches.h
[modify] https://crrev.com/1a5774e06f5d0a8794594e28a70e7c6b00106730/tools/metrics/histograms/histograms.xml

Issue 418867 has been merged into this issue.

 Issue 380328  has been merged into this issue.

The zoom level or pan around by using touch works when there is a browser. But not work for: wallpaper, file app.

It will be a problem in magnification mode if cannot pan around, meaning cannot exit the magnification mode any more.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/38b2fad16c23a6ce94509a76c249230ad6623c17

commit 38b2fad16c23a6ce94509a76c249230ad6623c17
Author: Yuki Awano <yawano@chromium.org>
Date: Thu Aug 17 03:00:49 2017

Enable touch support for screen magnifier by default

BUG= 670526 
TEST=Enable screen magnifier and pan around with 2 fingers or change
     zoom level with 3 fingers. It should work without changing the
     flag.

Change-Id: Id817f0159a9c067d427d2ae0906d8cf3c89dc04e
Reviewed-on: https://chromium-review.googlesource.com/601730
Commit-Queue: Yuki Awano <yawano@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#495061}
[modify] https://crrev.com/38b2fad16c23a6ce94509a76c249230ad6623c17/ash/magnifier/magnification_controller.cc
[modify] https://crrev.com/38b2fad16c23a6ce94509a76c249230ad6623c17/chrome/browser/about_flags.cc
[modify] https://crrev.com/38b2fad16c23a6ce94509a76c249230ad6623c17/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/38b2fad16c23a6ce94509a76c249230ad6623c17/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/38b2fad16c23a6ce94509a76c249230ad6623c17/chromeos/chromeos_switches.cc
[modify] https://crrev.com/38b2fad16c23a6ce94509a76c249230ad6623c17/chromeos/chromeos_switches.h

Request merge the CL in comment 8 (https://crrev.com/c/601730) to M61.

This bug requires manual review: There is .grd file changes and we are only 17 days from stable.
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), ketakid@(ChromeOS), govind@(Desktop)

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

ping.

Approving merge to M61 Chrome OS.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/08a35ce93db1d6506571fe4362394c0673dda19d

commit 08a35ce93db1d6506571fe4362394c0673dda19d
Author: Yuki Awano <yawano@chromium.org>
Date: Thu Aug 24 01:59:15 2017

Enable touch support for screen magnifier by default

BUG= 670526 
TEST=Enable screen magnifier and pan around with 2 fingers or change
     zoom level with 3 fingers. It should work without changing the
     flag.
TBR=oshima@chromium.org, yawano@chromium.org

(cherry picked from commit 38b2fad16c23a6ce94509a76c249230ad6623c17)

Change-Id: Id817f0159a9c067d427d2ae0906d8cf3c89dc04e
Reviewed-on: https://chromium-review.googlesource.com/601730
Commit-Queue: Yuki Awano <yawano@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#495061}
Reviewed-on: https://chromium-review.googlesource.com/631296
Reviewed-by: Yuki Awano <yawano@chromium.org>
Cr-Commit-Position: refs/branch-heads/3163@{#847}
Cr-Branched-From: ff259bab28b35d242e10186cd63af7ed404fae0d-refs/heads/master@{#488528}
[modify] https://crrev.com/08a35ce93db1d6506571fe4362394c0673dda19d/ash/magnifier/magnification_controller.cc
[modify] https://crrev.com/08a35ce93db1d6506571fe4362394c0673dda19d/chrome/browser/about_flags.cc
[modify] https://crrev.com/08a35ce93db1d6506571fe4362394c0673dda19d/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/08a35ce93db1d6506571fe4362394c0673dda19d/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/08a35ce93db1d6506571fe4362394c0673dda19d/chromeos/chromeos_switches.cc
[modify] https://crrev.com/08a35ce93db1d6506571fe4362394c0673dda19d/chromeos/chromeos_switches.h

Thank you! Merged the CL to M61.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c6f282275df729b57d13737b4c048271a9295c66

commit c6f282275df729b57d13737b4c048271a9295c66
Author: Yuki Awano <yawano@chromium.org>
Date: Thu Feb 01 10:49:08 2018

New touch support for screen magnification

- MagnificationController owns its GestureProvider to recognize gestures
  with screen coordinates of touch events. Logical coordinates of touch
  events cannot be used for gesture recognition as they are changed with
  viewport change: scroll, zoom.
- Use EventRewriter to see and rewrite touch events. Once
  MagnificationController detects two fingers pinch or scroll, it starts
  consuming all touch events not to confuse an app or a browser. It
  needs to rewrite events to dispatch touch cancel events.

      Confirm that user can change zoom level with two fingers pinch and
      pan around with two fingers scroll.
      Run ash_unittests:MagnificationControllerTest

Bug:  670526 
Test: Enable --ash-new-touch-support-for-screen-magnification flag.
Change-Id: I6906e5a6d93fea6f002a4fd3b83b616364a9f44b
Reviewed-on: https://chromium-review.googlesource.com/863403
Commit-Queue: Yuki Awano <yawano@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533625}
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/ash/magnifier/magnification_controller.cc
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/ash/magnifier/magnification_controller.h
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/ash/magnifier/magnification_controller_unittest.cc
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/ash/public/cpp/ash_switches.cc
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/ash/public/cpp/ash_switches.h
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/chrome/browser/about_flags.cc
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/chrome/browser/flag_descriptions.h
[modify] https://crrev.com/c6f282275df729b57d13737b4c048271a9295c66/tools/metrics/histograms/enums.xml

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41

commit d6b10e24afb1833aed4ab414fc3755fb7ebdcb41
Author: Yuki Awano <yawano@chromium.org>
Date: Wed Feb 07 01:16:00 2018

Remove --ash-new-touch-support-for-screen-magnification flag

- Enables new implementation of touch support for screen magnification
  by default.
- Removes the old implementation of touch support for screen
  magnification.

      around with two fingers scroll without any flag.
      Pass ash_unittests:MagnificationControllerTest

Bug:  670526 
Test: Confirm that you can change zoom level with pinch gesture and pan
Change-Id: Icf25edb2bceae28323075f857c3e74c2b4526dcc
Reviewed-on: https://chromium-review.googlesource.com/903306
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Yuki Awano <yawano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534861}
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/ash/magnifier/magnification_controller.cc
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/ash/magnifier/magnification_controller.h
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/ash/magnifier/magnification_controller_unittest.cc
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/ash/public/cpp/ash_switches.cc
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/ash/public/cpp/ash_switches.h
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/chrome/browser/about_flags.cc
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/chrome/browser/flag_descriptions.cc
[modify] https://crrev.com/d6b10e24afb1833aed4ab414fc3755fb7ebdcb41/chrome/browser/flag_descriptions.h