Bug 1633451 - Re-disable synthetic mousemoves on Android. r=geckoview-reviewers,m_kato

Differential Revision: https://phabricator.services.mozilla.com/D72691

modules/libpref/init/StaticPrefList.yaml

@@ -6018,9 +6018,12 @@
   value: true
   mirror: once
 
+# On Android, don't synth mouse move events after scrolling, as they cause
+# unexpected user-visible behaviour. Can remove this after bug 1633450 is
+# satisfactorily resolved.
 - name: layout.reflow.synthMouseMove
   type: bool
-  value: true
+  value: @IS_NOT_ANDROID@
   mirror: always
 
 # This pref is to be set by test code only.

testing/web-platform/meta/pointerevents/pointerevent_lostpointercapture_for_disconnected_node_in_shadow_dom.html.ini

@@ -0,0 +1,2 @@
+[pointerevent_lostpointercapture_for_disconnected_node_in_shadow_dom.html]
+  prefs: [layout.reflow.synthMouseMove:true]

testing/web-platform/meta/pointerevents/pointerevent_lostpointercapture_for_disconnected_shadow_host.html.ini

@@ -0,0 +1,2 @@
+[pointerevent_lostpointercapture_for_disconnected_shadow_host.html]
+  prefs: [layout.reflow.synthMouseMove:true]