Here's a real-world case of this warning being harmful (zero value due to existing use of touch-action, risks causing warning blindness): https://github.com/alvarotrigo/fullPage.js/issues/2362

I imagine that sort of case will be common, so I think it's important we get this fixed in M56.

Similarly, we might also need to worry about the "preventDefault called on an uncancelable touch event" warning.  Maybe we should similarly suppress it when touch-action is in effect?

review posted; https://codereview.chromium.org/2520423004/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6ea5974532e7cfea654c59181f1819e6805bb368

commit 6ea5974532e7cfea654c59181f1819e6805bb368
Author: dtapuska <dtapuska@chromium.org>
Date: Fri Nov 25 18:00:27 2016

Don't log a console warning when touch-action is used.

To avoid log fatigue for the developer only log the "you are prevent
defaulting a passive event listener" if no touch-action is used. If
touch-action is being used then it is clear that the developer is doing
this to interop with other browsers that don't support touch-action.

BUG= 667799 

Review-Url: https://codereview.chromium.org/2520423004
Cr-Commit-Position: refs/heads/master@{#434536}

[add] https://crrev.com/6ea5974532e7cfea654c59181f1819e6805bb368/third_party/WebKit/LayoutTests/fast/events/touch/touch-action-preventDefault-expected.txt
[add] https://crrev.com/6ea5974532e7cfea654c59181f1819e6805bb368/third_party/WebKit/LayoutTests/fast/events/touch/touch-action-preventDefault.html
[modify] https://crrev.com/6ea5974532e7cfea654c59181f1819e6805bb368/third_party/WebKit/Source/core/events/Event.cpp
[modify] https://crrev.com/6ea5974532e7cfea654c59181f1819e6805bb368/third_party/WebKit/Source/core/events/TouchEvent.cpp

Can someone please verify the fix?

If all looks good please request a merge to M56 Branch ( 2924) ASAP.

there is still one change to come.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/be1e266d539e2caeff5e7b174dba20e88d60f319

commit be1e266d539e2caeff5e7b174dba20e88d60f319
Author: dtapuska <dtapuska@chromium.org>
Date: Tue Nov 29 15:48:34 2016

Fix missing warning for canceling touchmove when in default not passive mode.

It appears that the the log error was dropped when the default mode enum
was added in change https://codereview.chromium.org/2475443004. Add a test
to ensure that it doesn't get dropped again.

BUG= 667799 

Review-Url: https://codereview.chromium.org/2536563003
Cr-Commit-Position: refs/heads/master@{#434998}

[modify] https://crrev.com/be1e266d539e2caeff5e7b174dba20e88d60f319/third_party/WebKit/LayoutTests/fast/events/touch/touch-event-cancelable-expected.txt
[modify] https://crrev.com/be1e266d539e2caeff5e7b174dba20e88d60f319/third_party/WebKit/LayoutTests/fast/events/touch/touch-event-cancelable.html
[modify] https://crrev.com/be1e266d539e2caeff5e7b174dba20e88d60f319/third_party/WebKit/Source/core/events/TouchEvent.cpp

Looks like OS-All, correct if wrong.

Your change meets the bar and is auto-approved for M56 (branch: 2924)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b7c3c8eb86af25ebba9d0254458a443a65a7c623

commit b7c3c8eb86af25ebba9d0254458a443a65a7c623
Author: Dave Tapuska <dtapuska@chromium.org>
Date: Wed Nov 30 22:10:20 2016

Don't log a console warning when touch-action is used.

To avoid log fatigue for the developer only log the "you are prevent
defaulting a passive event listener" if no touch-action is used. If
touch-action is being used then it is clear that the developer is doing
this to interop with other browsers that don't support touch-action.

BUG= 667799 

Review-Url: https://codereview.chromium.org/2520423004
Cr-Commit-Position: refs/heads/master@{#434536}
(cherry picked from commit 6ea5974532e7cfea654c59181f1819e6805bb368)

Review URL: https://codereview.chromium.org/2539183003 .

Cr-Commit-Position: refs/branch-heads/2924@{#214}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}

[add] https://crrev.com/b7c3c8eb86af25ebba9d0254458a443a65a7c623/third_party/WebKit/LayoutTests/fast/events/touch/touch-action-preventDefault-expected.txt
[add] https://crrev.com/b7c3c8eb86af25ebba9d0254458a443a65a7c623/third_party/WebKit/LayoutTests/fast/events/touch/touch-action-preventDefault.html
[modify] https://crrev.com/b7c3c8eb86af25ebba9d0254458a443a65a7c623/third_party/WebKit/Source/core/events/Event.cpp
[modify] https://crrev.com/b7c3c8eb86af25ebba9d0254458a443a65a7c623/third_party/WebKit/Source/core/events/TouchEvent.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/028ca146a4af5f6bcb765b34e14a47bbb1911da8

commit 028ca146a4af5f6bcb765b34e14a47bbb1911da8
Author: Dave Tapuska <dtapuska@chromium.org>
Date: Wed Nov 30 22:18:00 2016

Fix missing warning for canceling touchmove when in default not passive mode.

It appears that the the log error was dropped when the default mode enum
was added in change https://codereview.chromium.org/2475443004. Add a test
to ensure that it doesn't get dropped again.

BUG= 667799 

Review-Url: https://codereview.chromium.org/2536563003
Cr-Commit-Position: refs/heads/master@{#434998}
(cherry picked from commit be1e266d539e2caeff5e7b174dba20e88d60f319)

Review URL: https://codereview.chromium.org/2541003004 .

Cr-Commit-Position: refs/branch-heads/2924@{#215}
Cr-Branched-From: 3a87aecc31cd1ffe751dd72c04e5a96a1fc8108a-refs/heads/master@{#433059}

[modify] https://crrev.com/028ca146a4af5f6bcb765b34e14a47bbb1911da8/third_party/WebKit/LayoutTests/fast/events/touch/touch-event-cancelable-expected.txt
[modify] https://crrev.com/028ca146a4af5f6bcb765b34e14a47bbb1911da8/third_party/WebKit/LayoutTests/fast/events/touch/touch-event-cancelable.html
[modify] https://crrev.com/028ca146a4af5f6bcb765b34e14a47bbb1911da8/third_party/WebKit/Source/core/events/TouchEvent.cpp