Restore gesture requirement for async clipboard write access

[ShivanKaul]

Chromium 66+ implements Asynchronous Clipboard API. Chromium, in contrast to Safari and Firefox, allow a website to write to the user's clipboard using navigator.clipboard.writeText()/write() without a user gesture (only criteria is that the tab should be active).

We should require a user gesture (click, touch events) to enable use of navigator.clipboard.writeText() and navigator.clipboard.write(). Else, promise should reject.

Demo website that attempts to write to the user's clipboard: https://shivankaul.com/brave/clipboard-paste.html (if you get a success message, try to paste)

[ShivanKaul]

mozilla/standards-positions#89

[markg85]

Could this be re-evaluated?
Personally i really don't like this clipboard feature at all and want it gone in it's entirety.. That's probably not going to happen so please put it behind a permission request at the very least.

[androolloyd]

Am here to voice concern over this, its incredibly invasive and I would like to see it removed entirely from the Brave engine.

[bsclifton]

When it's time to try the fix, we'll need to go shields down to test the test page when fixing as EasyList is blocking what is required to test the gesture

[markg85]

Thank you for fixing brave!
Still, imho this entire feature shouldn't exist.. but having it be a permission check and false by default probably make it much less of an issue.

Interesting that this check was removed on the Chrome side for a freaking doodle new tab page purpose... It's beyond me how they can't (or won't) see that change to potentially be quite dangerous.

[mkarolin]

Test Plan
Please, see brave/brave-core#14901

[kjozwiak]

The above will require 1.43.91 or higher for 1.43.x verification 👍

[LaurenWags]

Verified with

Brave | 1.43.91 Chromium: 105.0.5195.102 (Official Build) (x86_64)
-- | --
Revision | 4c16f5ffcc2da70ee2600d5db77bed423ac03a5a-refs/branch-heads/5195_55@{#4}
OS | macOS Version 12.5.1 (Build 21G83)

Reproduced the issue using 1.43.88 and STR from brave/brave-core#14901 (comment).
Checked with shields up and shields down as per #16890 (comment).

1.43.88 Shields Up	1.43.88 Shields Down

Verified issue does not occur with 1.43.91. Checked with shields up and shields down.
When pasting in a new tab, my clipboard was no overwritten, it was the same text I had prior to visiting the page.

1.43.91 Shields Up	1.43.91 Shields Down

Note - Per brave/brave-core#14901 (comment), if you see "NotAllowedError" message this is ok as well. I did see this when changing shield settings.

[MadhaviSeelam]

Verification PASSED using

Brave | 1.43.91 Chromium: 105.0.5195.102 (Official Build) (64-bit)
-- | --
Revision | 4c16f5ffcc2da70ee2600d5db77bed423ac03a5a-refs/branch-heads/5195_55@{#4}
OS | Windows 11 Version 21H2 (Build 22000.856)

Reproduced the issue using 1.43.89 and STR from brave/brave-core#14901 (comment).
Checked with shields up and shields down as per #16890 (comment).

1.43.89 Shields Up	1.43.89 Shields Down

Verified issue does not occur with 1.43.91. Checked with shields up and shields down.
When pasting in a new tab, my clipboard was not overwritten, it was the same text I had prior to visiting the page.

1.43.91 Shields Up	1.43.91 Shields Down

Note - Per brave/brave-core#14901 (comment), if you see "NotAllowedError" message this is ok as well. I did see this when changing shield settings. (Refreshed the page and the error message was dismissed)

[btlechowski]

Verification passed on

Brave	1.43.92 Chromium: 105.0.5195.102 (Official Build) (64-bit)
Revision	4c16f5ffcc2da70ee2600d5db77bed423ac03a5a-refs/branch-heads/5195_55@{#4}
OS	Ubuntu 18.04 LTS

Verified brave/brave-core#14901

Reproduced in 1.43.88
Verified in 1.43.92

shields on 

shields down

[srirambv]

Verification passed on Oppo Reno 5 with Android 12 running 1.43.92 x64 build

• Reproduced the issue on 1.43.88
• Verified with both Shields Up/Down

1.43.88	1.43.92

---

Verification passed on Samsung Tab A with Android 10 running 1.43.92 x64 build

• Reproduced the issue on 1.43.88
• Verified with both Shields Up/Down

1.43.88	1.43.92