Paint collapsed borders of a table as one display item

third_party/WebKit/Source/core/layout/LayoutTableCell.cpp

Index: third_party/WebKit/Source/core/layout/LayoutTableCell.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableCell.cpp b/third_party/WebKit/Source/core/layout/LayoutTableCell.cpp
index e8195e90beb6ba30acf91563244f9fd807b29af2..97b3bf3ebfed49c2d8b510af90e23184882629fd 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableCell.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableCell.cpp
@@ -67,34 +67,6 @@ LayoutTableCell::LayoutTableCell(Element* element)
   updateColAndRowSpanFlags();
 }
 
-LayoutTableCell::CollapsedBorderValues::CollapsedBorderValues(
-    const LayoutTable& layoutTable,
-    const CollapsedBorderValue& startBorder,
-    const CollapsedBorderValue& endBorder,
-    const CollapsedBorderValue& beforeBorder,
-    const CollapsedBorderValue& afterBorder)
-    : m_layoutTable(layoutTable),
-      m_startBorder(startBorder),
-      m_endBorder(endBorder),
-      m_beforeBorder(beforeBorder),
-      m_afterBorder(afterBorder) {}
-
-void LayoutTableCell::CollapsedBorderValues::setCollapsedBorderValues(
-    const CollapsedBorderValues& other) {
-  m_startBorder = other.startBorder();
-  m_endBorder = other.endBorder();
-  m_beforeBorder = other.beforeBorder();
-  m_afterBorder = other.afterBorder();
-}
-
-String LayoutTableCell::CollapsedBorderValues::debugName() const {
-  return "CollapsedBorderValues";
-}
-
-LayoutRect LayoutTableCell::CollapsedBorderValues::visualRect() const {
-  return m_layoutTable.visualRect();
-}
-
 void LayoutTableCell::willBeRemovedFromTree() {
   LayoutBlockFlow::willBeRemovedFromTree();
 
@@ -500,7 +472,7 @@ void LayoutTableCell::styleDidChange(StyleDifference diff,
     return;
   if (!table->selfNeedsLayout() && !table->normalChildNeedsLayout() &&
       oldStyle && oldStyle->border() != style()->border())
-    table->invalidateCollapsedBorders();
+    table->invalidateCollapsedBorders(PaintInvalidationStyleChange);
 
   if (LayoutTableBoxComponent::doCellsHaveDirtyWidth(*this, *table, diff,
                                                      *oldStyle)) {
@@ -1303,7 +1275,7 @@ void LayoutTableCell::paint(const PaintInfo& paintInfo,
   TableCellPainter(*this).paint(paintInfo, paintOffset);
 }
 
-static void addBorderStyle(LayoutTable::CollapsedBorderValues& borderValues,
+static void addBorderStyle(Vector<CollapsedBorderValue>& borderValues,
                            CollapsedBorderValue borderValue) {
   if (!borderValue.isVisible())
     return;
@@ -1315,56 +1287,45 @@ static void addBorderStyle(LayoutTable::CollapsedBorderValues& borderValues,
   borderValues.append(borderValue);
 }
 
-void LayoutTableCell::collectBorderValues(
-    LayoutTable::CollapsedBorderValues& borderValues) {
-  CollapsedBorderValues newValues(
-      *table(), computeCollapsedStartBorder(), computeCollapsedEndBorder(),
-      computeCollapsedBeforeBorder(), computeCollapsedAfterBorder());
+bool LayoutTableCell::collectBorderValues(
+    Vector<CollapsedBorderValue>& borderValues) {
+  CollapsedBorderValues newValues = {
+      computeCollapsedStartBorder(), computeCollapsedEndBorder(),
+      computeCollapsedBeforeBorder(), computeCollapsedAfterBorder()};
 
   bool changed = false;
-  if (!newValues.startBorder().isVisible() &&
-      !newValues.endBorder().isVisible() &&
-      !newValues.beforeBorder().isVisible() &&
-      !newValues.afterBorder().isVisible()) {
+  if (!newValues.startBorder.isVisible() && !newValues.endBorder.isVisible() &&

[wkorman, 2016/12/05 05:49:22]

Just a thought: could improve readability if we move this to a
CollapsedBorderValues::allBordersVisible() method.

[Xianzhu, 2016/12/05 17:28:54]

Done.

+      !newValues.beforeBorder.isVisible() &&
+      !newValues.afterBorder.isVisible()) {
     changed = !!m_collapsedBorderValues;
     m_collapsedBorderValues = nullptr;
   } else if (!m_collapsedBorderValues) {
     changed = true;
-    m_collapsedBorderValues = wrapUnique(new CollapsedBorderValues(
-        *table(), newValues.startBorder(), newValues.endBorder(),
-        newValues.beforeBorder(), newValues.afterBorder()));
+    m_collapsedBorderValues = wrapUnique(new CollapsedBorderValues(newValues));
   } else {
     // We check visuallyEquals so that the table cell is invalidated only if a
     // changed collapsed border is visible in the first place.
-    changed = !m_collapsedBorderValues->startBorder().visuallyEquals(
-                  newValues.startBorder()) ||
-              !m_collapsedBorderValues->endBorder().visuallyEquals(
-                  newValues.endBorder()) ||
-              !m_collapsedBorderValues->beforeBorder().visuallyEquals(
-                  newValues.beforeBorder()) ||
-              !m_collapsedBorderValues->afterBorder().visuallyEquals(
-                  newValues.afterBorder());
+    changed = !m_collapsedBorderValues->startBorder.visuallyEquals(

[wkorman, 2016/12/05 05:49:22]

Similar just-a-thought: could add a
CollapsedBorderValues::bordersVisuallyEqual(CollapsedBorderValues) method to
coalesce the below.

[Xianzhu, 2016/12/05 17:28:54]

Done.

+                  newValues.startBorder) ||
+              !m_collapsedBorderValues->endBorder.visuallyEquals(
+                  newValues.endBorder) ||
+              !m_collapsedBorderValues->beforeBorder.visuallyEquals(
+                  newValues.beforeBorder) ||
+              !m_collapsedBorderValues->afterBorder.visuallyEquals(
+                  newValues.afterBorder);
     if (changed)
-      m_collapsedBorderValues->setCollapsedBorderValues(newValues);
+      *m_collapsedBorderValues = newValues;
   }
 
-  // If collapsed borders changed, invalidate the cell's display item client on
-  // the table's backing.
-  // TODO(crbug.com/451090#c5): Need a way to invalidate/repaint the borders
-  // only.
-  if (changed)
-    ObjectPaintInvalidator(*table())
-        .slowSetPaintingLayerNeedsRepaintAndInvalidateDisplayItemClient(
-            *this, PaintInvalidationStyleChange);
-
-  addBorderStyle(borderValues, newValues.startBorder());
-  addBorderStyle(borderValues, newValues.endBorder());
-  addBorderStyle(borderValues, newValues.beforeBorder());
-  addBorderStyle(borderValues, newValues.afterBorder());
+  addBorderStyle(borderValues, newValues.startBorder);
+  addBorderStyle(borderValues, newValues.endBorder);
+  addBorderStyle(borderValues, newValues.beforeBorder);
+  addBorderStyle(borderValues, newValues.afterBorder);
+  return changed;
 }
 
 void LayoutTableCell::sortBorderValues(
-    LayoutTable::CollapsedBorderValues& borderValues) {
+    Vector<CollapsedBorderValue>& borderValues) {
   std::sort(borderValues.begin(), borderValues.end(), compareBorders);
 }
 
@@ -1459,8 +1420,6 @@ void LayoutTableCell::invalidateDisplayItemClients(
     return;
 
   ObjectPaintInvalidator invalidator(*this);
-  if (m_collapsedBorderValues)
-    invalidator.invalidateDisplayItemClient(*m_collapsedBorderValues, reason);
   if (m_rowBackgroundDisplayItemClient) {
     invalidator.invalidateDisplayItemClient(*m_rowBackgroundDisplayItemClient,
                                             reason);