Fix painting background for composited table cells in a non-composited row.

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 b842de0d1adf12959601e2381e614de54c9f9d27..7774d759996f234fac7bc24bfa309b99ebeff0cb 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableCell.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableCell.cpp
@@ -46,7 +46,8 @@ using namespace HTMLNames;
 struct SameSizeAsLayoutTableCell : public LayoutBlockFlow {
   unsigned bitfields;
   int paddings[2];
-  void* pointer;
+  void* pointer1;
+  void* pointer2;
 };
 
 static_assert(sizeof(LayoutTableCell) == sizeof(SameSizeAsLayoutTableCell),
@@ -463,6 +464,24 @@ int LayoutTableCell::cellBaselinePosition() const {
   return (borderBefore() + paddingBefore() + contentLogicalHeight()).toInt();
 }
 
+void LayoutTableCell::createCompositedCellDisplayItemClients() {
+  if (!usesCompositedCellDisplayItemClients())
+    return;
+
+  if (row()->styleRef().hasBackground() && !m_rowBackgroundDisplayItemClient) {

[Xianzhu, 2016/11/16 20:39:03]

We should remove the hasbackground() condition for cases that the row
doesn't have background, but section or col/colgroup has, in case that the row
is not composited.

[wkorman, 2016/11/16 21:42:45]

Done.

+    m_rowBackgroundDisplayItemClient =
+        wrapUnique(new LayoutTableCell::RowBackgroundDisplayItemClient(*row()));
+  }
+}
+
+void LayoutTableCell::ensureIsReadyForPaintInvalidation() {
+  LayoutBlockFlow::ensureIsReadyForPaintInvalidation();
+  // Below handles the case where a page starts out in a state where the table
+  // cell compositing state and its container styling is such that one or more
+  // special display item clients are needed.
+  createCompositedCellDisplayItemClients();

[Xianzhu, 2016/11/16 20:39:03]

With the call to createCompositedCellDisplayItemClients() in
TablePaintInvalidator replaced with ensureIsreadyForPaintInvalidation(), you can
directly inline the function here.

[wkorman, 2016/11/16 21:42:44]

Done.

+}
+
 void LayoutTableCell::styleDidChange(StyleDifference diff,
                                      const ComputedStyle* oldStyle) {
   DCHECK_EQ(style()->display(), EDisplay::TableCell);
@@ -508,6 +527,18 @@ void LayoutTableCell::styleDidChange(StyleDifference diff,
   }
 }
 
+LayoutTableCell::RowBackgroundDisplayItemClient::RowBackgroundDisplayItemClient(
+    const LayoutTableRow& layoutTableRow)
+    : m_layoutTableRow(layoutTableRow) {}
+
+String LayoutTableCell::RowBackgroundDisplayItemClient::debugName() const {
+  return "RowBackground";
+}
+
+LayoutRect LayoutTableCell::RowBackgroundDisplayItemClient::visualRect() const {
+  return m_layoutTableRow.visualRect();
+}
+
 // The following rules apply for resolving conflicts and figuring out which
 // border to use.
 // (1) Borders with the 'border-style' of 'hidden' take precedence over all
@@ -1416,7 +1447,7 @@ bool LayoutTableCell::backgroundIsKnownToBeOpaqueInRect(
   return LayoutBlockFlow::backgroundIsKnownToBeOpaqueInRect(localRect);
 }
 
-bool LayoutTableCell::usesTableAsAdditionalDisplayItemClient() const {
+bool LayoutTableCell::usesCompositedCellDisplayItemClients() const {
   // In certain cases such as collapsed borders for composited table cells we
   // paint content for the cell into the table graphics layer backing and so
   // must use the table's visual rect.
@@ -1426,11 +1457,18 @@ bool LayoutTableCell::usesTableAsAdditionalDisplayItemClient() const {
 
 void LayoutTableCell::invalidateDisplayItemClients(
     PaintInvalidationReason reason) const {
-  if (m_collapsedBorderValues && usesTableAsAdditionalDisplayItemClient()) {
-    ObjectPaintInvalidator(*this).invalidateDisplayItemClient(
-        *m_collapsedBorderValues, reason);
-  }
   LayoutBlockFlow::invalidateDisplayItemClients(reason);
+
+  if (!usesCompositedCellDisplayItemClients())
+    return;
+
+  ObjectPaintInvalidator invalidator(*this);
+  if (m_collapsedBorderValues)
+    invalidator.invalidateDisplayItemClient(*m_collapsedBorderValues, reason);
+  if (m_rowBackgroundDisplayItemClient) {
+    invalidator.invalidateDisplayItemClient(*m_rowBackgroundDisplayItemClient,
+                                            reason);
+  }
 }
 
 // TODO(lunalu): Deliberately dump the "inner" box of table cells, since that