diff --git a/gfx/layers/apz/src/APZCTreeManager.cpp b/gfx/layers/apz/src/APZCTreeManager.cpp
index eae58be4e72e..da77c86120d4 100644
--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -3559,6 +3559,9 @@ bool APZCTreeManager::GetAPZTestData(LayersId aLayersId,
if (apzc->GetCheckerboardMagnitude(clippedBounds)) {
apzcState += "checkerboarding,";
}
+ if (apzc->IsOverscrolled()) {
+ apzcState += "overscrolled,";
+ }
aOutData->RecordAdditionalData(viewId, apzcState);
}
}
diff --git a/gfx/layers/apz/test/mochitest/helper_overscroll_in_apz_test_data.html b/gfx/layers/apz/test/mochitest/helper_overscroll_in_apz_test_data.html
new file mode 100644
index 000000000000..ed05f25819cb
--- /dev/null
+++ b/gfx/layers/apz/test/mochitest/helper_overscroll_in_apz_test_data.html
@@ -0,0 +1,29 @@
+
+
+
+
A simple test checks "overscrolled" info in APZTestData
+Tests scroll anchoring updates in-progress wheel scrolling __relatively__
+
+
+
+
+
diff --git a/gfx/layers/apz/test/mochitest/test_group_touchevents-5.html b/gfx/layers/apz/test/mochitest/test_group_touchevents-5.html
index f91d1c6145a5..d4ae624a69c3 100644
--- a/gfx/layers/apz/test/mochitest/test_group_touchevents-5.html
+++ b/gfx/layers/apz/test/mochitest/test_group_touchevents-5.html
@@ -15,7 +15,11 @@ var subtests = [
{"file": "helper_bug1669625.html", "dp_suppression": false},
{"file": "helper_touch_drag_root_scrollbar.html", "prefs": [["apz.allow_zooming", true]]},
{"file": "helper_touch_drag_root_scrollbar.html", "prefs": [["apz.allow_zooming", false]]},
-
+ {"file": "helper_overscroll_in_apz_test_data.html", "prefs": [
+ ["apz.overscroll.enabled", true],
+ ["apz.overscroll.test_async_scroll_offset.enabled", true],
+ ["apz.test.logging_enabled", true],
+ ]},
// Add new subtests here. If this starts timing out because it's taking too
// long, create a test_group_touchevents-6.html file. Refer to 1423011#c57
// for more details.