Bugzilla

To give more context, it seems that [GeckoEditable.icNotifyIME](https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoEditable.java#1324) calls [GeckoEditable.softInput](https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoEditable.java#1621), which calls [GeckoViewContentChild.receiveMessage](https://searchfox.org/mozilla-central/rev/0376cbf447efa16922c550da3bfd783b916e35d3/mobile/android/chrome/geckoview/GeckoViewContentChild.js#171), which calls [nsDOMWindowUtils.ZoomToFocusedInput](https://searchfox.org/mozilla-central/source/dom/base/nsDOMWindowUtils.cpp#2443) which also [scrolls to the element](https://searchfox.org/mozilla-central/source/dom/base/nsDOMWindowUtils.cpp#2518). At the latter place, scrolling needs to be prevented. The place could probably notified by using a new flag `EditableListener.NOTIFY_IME_OPEN_VKB_PREVENT_SCROLL`.

To give more context, it seems that [GeckoEditable.icNotifyIME](https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoEditable.java#1324) calls [GeckoEditable.softInput](https://searchfox.org/mozilla-central/source/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoEditable.java#1621), which calls [GeckoViewContentChild.receiveMessage](https://searchfox.org/mozilla-central/rev/0376cbf447efa16922c550da3bfd783b916e35d3/mobile/android/chrome/geckoview/GeckoViewContentChild.js#171), which calls [nsDOMWindowUtils.ZoomToFocusedInput](https://searchfox.org/mozilla-central/source/dom/base/nsDOMWindowUtils.cpp#2443) which also [scrolls to the element](https://searchfox.org/mozilla-central/source/dom/base/nsDOMWindowUtils.cpp#2518). At the latter place, scrolling needs to be prevented. The place could probably be notified by using a new flag `EditableListener.NOTIFY_IME_OPEN_VKB_PREVENT_SCROLL`.