Fix border radius on composited children.

third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
index 7c500884885c0045d20b7a4ca37ac354ba8e12ab..14294b9cec355ece66bdc6391a98e1182aa80ee7 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
@@ -251,6 +251,19 @@ static bool shouldRepaintSubsequence(
   return needsRepaint;
 }
 
+void adjustOffsetForAncestorClippingMask(

[chrishtr, 2016/12/07 19:16:24]

This is now dead code.

+    const PaintLayer& childLayer,
+    const PaintLayer& ancestorLayer,
+    LayoutPoint& offset)
+{
+    // Adjust the offset to reflect the fact that the fragment is
+    // positioned for the clipping container object.
+    LayoutPoint childOffsetToAncestor;
+    childLayer.convertToLayerCoords(&ancestorLayer, childOffsetToAncestor);
+    offset.move(
+        LayoutSize(-childOffsetToAncestor.x(), -childOffsetToAncestor.y()));
+}
+
 PaintResult PaintLayerPainter::paintLayerContents(
     GraphicsContext& context,
     const PaintLayerPaintingInfo& paintingInfoArg,
@@ -374,7 +387,8 @@ PaintResult PaintLayerPainter::paintLayerContents(
   // scrolling contents and scrollbars.
   if (m_paintLayer.layoutObject()->hasClipPath() &&
       (!m_paintLayer.needsCompositedScrolling() ||
-       (paintFlags & PaintLayerPaintingChildClippingMaskPhase))) {
+       (paintFlags & (PaintLayerPaintingChildClippingMaskPhase |
+                      PaintLayerPaintingAncestorClippingMaskPhase)))) {
     paintingInfo.ancestorHasClipPathClipping = true;
 
     LayoutRect referenceBox(m_paintLayer.boxForClipPath());
@@ -430,19 +444,45 @@ PaintResult PaintLayerPainter::paintLayerContents(
     // TODO(trchen): We haven't decided how to handle visual fragmentation with
     // SPv2.  Related thread
     // https://groups.google.com/a/chromium.org/forum/#!topic/graphics-dev/81XuWFf-mxM
+    LayoutPoint offsetToClipper;
+    PaintLayer* paintLayerForFragments = &m_paintLayer;
+    if (paintFlags & PaintLayerPaintingAncestorClippingMaskPhase) {
+      // Compute fragments and their clips with respect to the clipping
+      // container. The paint rect is in this layer's space, so convert it
+      // to the clipper's layer's space. The rootLayer is also changed to
+      // the clipper's layer to simplify coordinate system adjustments.
+      paintLayerForFragments = m_paintLayer.clippingContainer()->enclosingLayer();
+      localPaintingInfo.rootLayer = paintLayerForFragments;
+      m_paintLayer.convertToLayerCoords(localPaintingInfo.rootLayer, offsetToClipper);
+      localPaintingInfo.paintDirtyRect.moveBy(offsetToClipper);
+    }
+
     if (fragmentPolicy == ForceSingleFragment ||
-        RuntimeEnabledFeatures::slimmingPaintV2Enabled())
-      m_paintLayer.appendSingleFragmentIgnoringPagination(
+        RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+      paintLayerForFragments->appendSingleFragmentIgnoringPagination(
           layerFragments, localPaintingInfo.rootLayer,
           localPaintingInfo.paintDirtyRect, cacheSlot,
-          IgnoreOverlayScrollbarSize, respectOverflowClip, &offsetFromRoot,
-          localPaintingInfo.subPixelAccumulation);
-    else
-      m_paintLayer.collectFragments(layerFragments, localPaintingInfo.rootLayer,
-                                    localPaintingInfo.paintDirtyRect, cacheSlot,
-                                    IgnoreOverlayScrollbarSize,
-                                    respectOverflowClip, &offsetFromRoot,
-                                    localPaintingInfo.subPixelAccumulation);
+          IgnoreOverlayScrollbarSize, respectOverflowClip,
+          &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
+    } else {
+      paintLayerForFragments->collectFragments(
+          layerFragments, localPaintingInfo.rootLayer,
+          localPaintingInfo.paintDirtyRect, cacheSlot,
+          IgnoreOverlayScrollbarSize, respectOverflowClip,
+          &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
+    }
+
+    if (paintFlags & PaintLayerPaintingAncestorClippingMaskPhase) {
+      // Fragment offsets have been computed in the clipping container's
+      // layer's coordinate system, but for the rest of painting we need
+      // them in the layer coordinate. So move them and the foreground rect
+      // that is also in the clipper's space.
+      LayoutSize negativeOffset(-offsetToClipper.x(), -offsetToClipper.y());
+      for (auto& fragment: layerFragments) {
+        fragment.foregroundRect.move(negativeOffset);
+        fragment.paginationOffset.move(negativeOffset);
+      }
+    }
 
     if (shouldPaintContent) {
       // TODO(wangxianzhu): This is for old slow scrolling. Implement similar
@@ -546,7 +586,8 @@ PaintResult PaintLayerPainter::paintLayerContents(
       shouldPaintContent && m_paintLayer.layoutObject()->hasMask() &&
       !selectionOnly;
   bool shouldPaintClippingMask =
-      (paintFlags & PaintLayerPaintingChildClippingMaskPhase) &&
+      (paintFlags & (PaintLayerPaintingChildClippingMaskPhase |
+                     PaintLayerPaintingAncestorClippingMaskPhase)) &&
       shouldPaintContent && !selectionOnly;
 
   if (shouldPaintMask)
@@ -625,6 +666,7 @@ PaintResult PaintLayerPainter::paintLayerWithTransform(
       object->container() == view && view->pageLogicalHeight();
   PaintLayer* paginationLayer = m_paintLayer.enclosingPaginationLayer();
   PaintLayerFragments fragments;
+
   // TODO(crbug.com/619094): Figure out the correct behaviour for fixed position
   // objects in paged media with vertical writing modes.
   if (isFixedPosObjectInPagedMedia && view->isHorizontalWritingMode()) {
@@ -721,7 +763,7 @@ PaintResult PaintLayerPainter::paintLayerWithTransform(
                             UseCounter::ClipCssOfFixedPositionElement);
         clipRecorder.emplace(context, *parentLayer->layoutObject(),
                              DisplayItem::kClipLayerParent, clipRectForFragment,
-                             &paintingInfo, fragment.paginationOffset,
+                             paintingInfo.rootLayer, fragment.paginationOffset,
                              paintFlags);
       }
     }
@@ -859,7 +901,8 @@ void PaintLayerPainter::paintOverflowControlsForFragments(
     if (needsToClip(localPaintingInfo, fragment.backgroundRect)) {
       clipRecorder.emplace(context, *m_paintLayer.layoutObject(),
                            DisplayItem::kClipLayerOverflowControls,
-                           fragment.backgroundRect, &localPaintingInfo,
+                           fragment.backgroundRect,
+                           localPaintingInfo.rootLayer,
                            fragment.paginationOffset, paintFlags);
     }
 
@@ -910,8 +953,8 @@ void PaintLayerPainter::paintFragmentWithPhase(
     }
 
     clipRecorder.emplace(context, *m_paintLayer.layoutObject(), clipType,
-                         clipRect, &paintingInfo, fragment.paginationOffset,
-                         paintFlags, clippingRule);
+                         clipRect, paintingInfo.rootLayer,
+                         fragment.paginationOffset, paintFlags, clippingRule);
   }
 
   LayoutRect newCullRect(clipRect.rect());
@@ -983,7 +1026,8 @@ void PaintLayerPainter::paintForegroundForFragments(
       needsToClip(localPaintingInfo, layerFragments[0].foregroundRect)) {
     clipRecorder.emplace(context, *m_paintLayer.layoutObject(),
                          DisplayItem::kClipLayerForeground,
-                         layerFragments[0].foregroundRect, &localPaintingInfo,
+                         layerFragments[0].foregroundRect,
+                         localPaintingInfo.rootLayer,
                          layerFragments[0].paginationOffset, paintFlags);
     clipState = HasClipped;
   }