[PE] Invalidate painting layer when transform invertibility changes

PaintLayerPainter::PaintLayerWithAdjustedRoot skips painting of a layer whose transform is not invertible, so we need to repaint the layer when invertible status changes. Bug: 853047 Change-Id: Ie24af4de933336e888065e993e473ab8ed4711a4 Reviewed-on: https://chromium-review.googlesource.com/1105298Reviewed-by: Tien-Ren Chen <trchen@chromium.org> Commit-Queue: Tien-Ren Chen <trchen@chromium.org> Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org> Cr-Commit-Position: refs/heads/master@{#568269}

[PE] Invalidate painting layer when transform invertibility changes
PaintLayerPainter::PaintLayerWithAdjustedRoot skips painting of a layer whose transform is not invertible, so we need to repaint the layer when invertible status changes. Bug: 853047 Change-Id: Ie24af4de933336e888065e993e473ab8ed4711a4 Reviewed-on: https://chromium-review.googlesource.com/1105298Reviewed-by: Tien-Ren Chen <trchen@chromium.org> Commit-Queue: Tien-Ren Chen <trchen@chromium.org> Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org> Cr-Commit-Position: refs/heads/master@{#568269}
8b3bc88c · Xianzhu Wang · Commit Bot · bfcc445d · 8b3bc88c · 8b3bc88c
Commit 8b3bc88c authored Jun 19, 2018 by Xianzhu Wang Committed by Commit Bot Jun 19, 2018
3 changed files
--- a/third_party/WebKit/LayoutTests/paint/invalidation/transform/scale-zero-to-non-zero-expected.html
+++ b/third_party/WebKit/LayoutTests/paint/invalidation/transform/scale-zero-to-non-zero-expected.html
+<!DOCTYPE html>
+<div id="target" style="width: 200px; height: 200px; background: blue"></div>
--- a/third_party/WebKit/LayoutTests/paint/invalidation/transform/scale-zero-to-non-zero.html
+++ b/third_party/WebKit/LayoutTests/paint/invalidation/transform/scale-zero-to-non-zero.html
+<!DOCTYPE html>
+<div id="target" style="width: 100px; height: 100px; background: blue; transform: scale(0); transform-origin: 0 0"></div>
+<script src="../../../resources/run-after-layout-and-paint.js"></script>
+<script>
+runAfterLayoutAndPaint(function() {
+  target.style.transform = "scale(2)";
+}, true);
+</script>
--- a/third_party/blink/renderer/core/layout/layout_box_model_object.cc
+++ b/third_party/blink/renderer/core/layout/layout_box_model_object.cc
@@ -431,11 +431,30 @@ void LayoutBoxModelObject::StyleDidChange(StyleDifference diff,
  }

  if (old_style && RuntimeEnabledFeatures::SlimmingPaintV175Enabled() &&
-      old_style->BackfaceVisibility() != StyleRef().BackfaceVisibility() &&
-      HasLayer()) {
-    // We need to repaint the layer to update the backface visibility value of
-    // the paint chunk.
-    Layer()->SetNeedsRepaint();
+      HasLayer() && !Layer()->NeedsRepaint()) {
+    if (old_style->BackfaceVisibility() != StyleRef().BackfaceVisibility()) {
+      // We need to repaint the layer to update the backface visibility value of
+      // the paint chunk.
+      Layer()->SetNeedsRepaint();
+    } else if (diff.TransformChanged() &&
+               (RuntimeEnabledFeatures::SlimmingPaintV2Enabled() ||
+                !Layer()->HasStyleDeterminedDirectCompositingReasons())) {
+      // PaintLayerPainter::PaintLayerWithAdjustedRoot skips painting of a layer
+      // whose transform is not invertible, so we need to repaint the layer when
+      // invertible status changes.
+      TransformationMatrix old_transform;
+      TransformationMatrix new_transform;
+      old_style->ApplyTransform(
+          old_transform, LayoutSize(), ComputedStyle::kExcludeTransformOrigin,
+          ComputedStyle::kExcludeMotionPath,
+          ComputedStyle::kIncludeIndependentTransformProperties);
+      StyleRef().ApplyTransform(
+          new_transform, LayoutSize(), ComputedStyle::kExcludeTransformOrigin,
+          ComputedStyle::kExcludeMotionPath,
+          ComputedStyle::kIncludeIndependentTransformProperties);
+      if (old_transform.IsInvertible() != new_transform.IsInvertible())
+        Layer()->SetNeedsRepaint();
+    }
  }
 }