From 25b39cb380a9aab3a33299249dbca1e1a964e162 Mon Sep 17 00:00:00 2001
From: Marco Castelluccio <mcastelluccio@mozilla.com>
Date: Thu, 3 Oct 2019 03:52:15 +0000
Subject: [PATCH] Bug 1421384 - Inherit touch-action flags down in the
 compositor hit-test infos. r=miko

Per the touch-action spec, the effective touch-action on an element includes
touch-action restrictions from ancestor elements up to and including the
element that has the "default action". This patch implements that behaviour
so that WebRender gets correct touch-action values on its display items.

MozReview-Commit-ID: Cw5uqAsE9qm

UltraBlame original commit: 6659f392f4af0cef3cb4a5e19eef7e0e1b045f37
---
 gfx/layers/apz/test/mochitest/mochitest.ini |  6 --
 layout/generic/nsFrame.cpp                  | 63 +++++++++++++++++++++
 layout/painting/nsDisplayList.h             | 11 ++++
 3 files changed, 74 insertions(+), 6 deletions(-)

diff --git a/gfx/layers/apz/test/mochitest/mochitest.ini b/gfx/layers/apz/test/mochitest/mochitest.ini
index e7e755a959177..8ae954ee2ad57 100644
--- a/gfx/layers/apz/test/mochitest/mochitest.ini
+++ b/gfx/layers/apz/test/mochitest/mochitest.ini
@@ -361,9 +361,6 @@ skip
 -
 if
 =
-webrender
-|
-|
 (
 verify
 &
@@ -380,9 +377,6 @@ win
 '
 )
 )
-#
-bug
-1424752
 [
 test_group_wheelevents
 .
diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index 28da7baf75676..4d6299727a52e 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -52962,6 +52962,45 @@ eDispatchToContent
 ;
 }
 }
+CompositorHitTestInfo
+inheritedTouchAction
+=
+CompositorHitTestInfo
+:
+:
+eInvisibleToHitTest
+;
+if
+(
+nsDisplayCompositorHitTestInfo
+*
+parentInfo
+=
+aBuilder
+-
+>
+GetCompositorHitTestInfo
+(
+)
+)
+{
+inheritedTouchAction
+=
+(
+parentInfo
+-
+>
+HitTestInfo
+(
+)
+&
+CompositorHitTestInfo
+:
+:
+eTouchActionMask
+)
+;
+}
 nsIFrame
 *
 touchActionFrame
@@ -52990,7 +53029,31 @@ do_QueryFrame
 scrollFrame
 )
 ;
+CompositorHitTestInfo
+panMask
+=
+CompositorHitTestInfo
+:
+:
+eTouchActionPanXDisabled
+|
+CompositorHitTestInfo
+:
+:
+eTouchActionPanYDisabled
+;
+inheritedTouchAction
+&
+=
+~
+panMask
+;
 }
+result
+|
+=
+inheritedTouchAction
+;
 const
 uint32_t
 touchAction
diff --git a/layout/painting/nsDisplayList.h b/layout/painting/nsDisplayList.h
index 30ca6ec1970dd..ca6d017e76b3b 100644
--- a/layout/painting/nsDisplayList.h
+++ b/layout/painting/nsDisplayList.h
@@ -2397,6 +2397,17 @@ mCompositorHitTestInfo
 aHitTestInfo
 ;
 }
+nsDisplayCompositorHitTestInfo
+*
+GetCompositorHitTestInfo
+(
+)
+const
+{
+return
+mCompositorHitTestInfo
+;
+}
 void
 BuildCompositorHitTestInfoIfNeeded
 (