[PaintTouchActionRect] Calculate scrolling LayoutReplaced hit test rects

This is a followup patch to [1] and paints LayoutReplaced hit test rects
into the scrolling contents layer. In this way we don't need to repaint
on every scroll change.

[1] https://crrev.com/603335

Bug: 888269
Change-Id: Ic8196f59b8a2f7d08285c5234ed562a61386ee6b
Reviewed-on: https://chromium-review.googlesource.com/c/1310754
Commit-Queue: Philip Rogers <pdr@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605378}

third_party/WebKit/LayoutTests/virtual/paint-touchaction-rects/fast/events/touch/compositor-touch-hit-rects-svg-root-expected.txt

-: #document scrolling (9, 9, 51, 52)
+: #document scrolling (8, 8, 53, 54)
 
 

third_party/blink/renderer/core/paint/box_painter.cc

@@ -254,12 +254,6 @@ void BoxPainter::RecordHitTestData(const PaintInfo& paint_info,
                                    const LayoutPoint& paint_offset,
                                    const LayoutRect& paint_rect,
                                    const DisplayItemClient& background_client) {
-  // TODO(sunxd): ReplacedPainter only record hit test data for svg root which
-  // skips clip. We should move the conditions and ReplacedPainter's
-  // RecordHitTestData here.
-  if (layout_box_.IsLayoutReplaced())
-    return;
-
   // Hit test display items are only needed for compositing. This flag is used
   // for for printing and drag images which do not need hit testing.
   if (paint_info.GetGlobalPaintFlags() & kGlobalPaintFlattenCompositingLayers)

third_party/blink/renderer/core/paint/replaced_painter.cc

@@ -138,10 +138,6 @@ void ReplacedPainter::Paint(const PaintInfo& paint_info) {
   if (skip_clip || !layout_replaced_.PhysicalContentBoxRect().IsEmpty()) {
     ScopedReplacedContentPaintState content_paint_state(paint_state,
                                                         layout_replaced_);
-    if (RuntimeEnabledFeatures::PaintTouchActionRectsEnabled()) {
-      RecordHitTestData(content_paint_state.GetPaintInfo(),
-                        content_paint_state.PaintOffset());
-    }
     layout_replaced_.PaintReplaced(content_paint_state.GetPaintInfo(),
                                    content_paint_state.PaintOffset());
   }
@@ -176,30 +172,6 @@ void ReplacedPainter::Paint(const PaintInfo& paint_info) {
   }
 }
 
-void ReplacedPainter::RecordHitTestData(const PaintInfo& paint_info,
-                                        const LayoutPoint& paint_offset) {
-  // Hit test display items are only needed for compositing. This flag is used
-  // for for printing and drag images which do not need hit testing.
-  if (paint_info.GetGlobalPaintFlags() & kGlobalPaintFlattenCompositingLayers)
-    return;
-
-  if (paint_info.phase != PaintPhase::kForeground)
-    return;
-
-  // If an object is not visible, it does not participate in hit testing.
-  if (layout_replaced_.StyleRef().Visibility() != EVisibility::kVisible)
-    return;
-
-  auto touch_action = layout_replaced_.EffectiveWhitelistedTouchAction();
-  if (touch_action == TouchAction::kTouchActionAuto)
-    return;
-
-  auto rect = layout_replaced_.VisualOverflowRect();
-  rect.MoveBy(paint_offset);
-  HitTestData::RecordHitTestRect(paint_info.context, layout_replaced_,
-                                 HitTestRect(rect, touch_action));
-}
-
 bool ReplacedPainter::ShouldPaint(const ScopedPaintState& paint_state) const {
   const auto& paint_info = paint_state.GetPaintInfo();
   if (paint_info.phase != PaintPhase::kForeground &&

third_party/blink/renderer/core/paint/replaced_painter.h

@@ -26,10 +26,6 @@ class ReplacedPainter {
   bool ShouldPaint(const ScopedPaintState&) const;
 
  private:
-  // Paint a hit test display item and record hit test data. This should be
-  // called in the background paint phase even if there is no other painted
-  // content.
-  void RecordHitTestData(const PaintInfo&, const LayoutPoint& paint_offset);
   const LayoutReplaced& layout_replaced_;
 };