New display item caching

Source/core/paint/ViewDisplayListTest.cpp

Index: Source/core/paint/ViewDisplayListTest.cpp
diff --git a/Source/core/paint/ViewDisplayListTest.cpp b/Source/core/paint/ViewDisplayListTest.cpp
index b095b4e06cbc4f6d77b82ebb3e5b2cab37aa7682..8e2429c6caa48d6555657c914cdc90552178b4e2 100644
--- a/Source/core/paint/ViewDisplayListTest.cpp
+++ b/Source/core/paint/ViewDisplayListTest.cpp
@@ -519,5 +519,57 @@ TEST_F(ViewDisplayListTest, FullDocumentPaintingWithCaret)
         TestDisplayItem(divRenderer, DisplayItem::DrawingPaintPhaseCaret));
 }
 
+TEST_F(ViewDisplayListTest, ComplexUpdateSwapOrder)
+{
+    setBodyInnerHTML("<div id='container1'><div id='content1'></div></div>"
+        "<div id='container2'><div id='content2'></div></div>");
+    RenderObject* container1 = document().body()->firstChild()->renderer();
+    RenderObject* content1 = document().body()->firstChild()->firstChild()->renderer();
+    RenderObject* container2 = document().body()->firstChild()->nextSibling()->renderer();
+    RenderObject* content2 = document().body()->firstChild()->nextSibling()->firstChild()->renderer();
+    GraphicsContext context(nullptr, &rootDisplayItemList());
+
+    drawRect(&context, container1, PaintPhaseBlockBackground, FloatRect(100, 100, 100, 100));
+    drawRect(&context, content1, PaintPhaseBlockBackground, FloatRect(100, 100, 50, 200));
+    drawRect(&context, content1, PaintPhaseForeground, FloatRect(100, 100, 50, 200));
+    drawRect(&context, container1, PaintPhaseForeground, FloatRect(100, 100, 100, 100));
+    drawRect(&context, container2, PaintPhaseBlockBackground, FloatRect(100, 200, 100, 100));
+    drawRect(&context, content2, PaintPhaseBlockBackground, FloatRect(100, 200, 50, 200));
+    drawRect(&context, content2, PaintPhaseForeground, FloatRect(100, 200, 50, 200));
+    drawRect(&context, container2, PaintPhaseForeground, FloatRect(100, 200, 100, 100));
+    rootDisplayItemList().endNewPaints();
+
+    EXPECT_DISPLAY_LIST(rootDisplayItemList().paintList(), 8,
+        TestDisplayItem(container1, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content1, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content1, DisplayItem::DrawingPaintPhaseForeground),
+        TestDisplayItem(container1, DisplayItem::DrawingPaintPhaseForeground),
+        TestDisplayItem(container2, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content2, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content2, DisplayItem::DrawingPaintPhaseForeground),
+        TestDisplayItem(container2, DisplayItem::DrawingPaintPhaseForeground));
+
+    rootDisplayItemList().invalidate(container1->displayItemClient());
+    drawRect(&context, container2, PaintPhaseBlockBackground, FloatRect(100, 200, 100, 100));
+    drawRect(&context, content2, PaintPhaseBlockBackground, FloatRect(100, 200, 50, 200));
+    drawRect(&context, content2, PaintPhaseForeground, FloatRect(100, 200, 50, 200));
+    drawRect(&context, container2, PaintPhaseForeground, FloatRect(100, 200, 100, 100));
+    drawRect(&context, container1, PaintPhaseBlockBackground, FloatRect(100, 100, 100, 100));
+    drawRect(&context, content1, PaintPhaseBlockBackground, FloatRect(100, 100, 50, 200));
+    drawRect(&context, content1, PaintPhaseForeground, FloatRect(100, 100, 50, 200));
+    drawRect(&context, container1, PaintPhaseForeground, FloatRect(100, 100, 100, 100));
+    rootDisplayItemList().endNewPaints();
+
+    EXPECT_DISPLAY_LIST(rootDisplayItemList().paintList(), 8,
+        TestDisplayItem(container2, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content2, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content2, DisplayItem::DrawingPaintPhaseForeground),
+        TestDisplayItem(container2, DisplayItem::DrawingPaintPhaseForeground),
+        TestDisplayItem(container1, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content1, DisplayItem::DrawingPaintPhaseBlockBackground),
+        TestDisplayItem(content1, DisplayItem::DrawingPaintPhaseForeground),
+        TestDisplayItem(container1, DisplayItem::DrawingPaintPhaseForeground));
+}
+
 } // anonymous namespace
 } // namespace blink