Blink-side contiguous allocation of display items.

Source/platform/graphics/paint/DisplayItemListTest.cpp

Index: Source/platform/graphics/paint/DisplayItemListTest.cpp
diff --git a/Source/platform/graphics/paint/DisplayItemListTest.cpp b/Source/platform/graphics/paint/DisplayItemListTest.cpp
index ef71fb1d9fd2d9171ef35488e136f555b821a084..ae69bbfd5d04d13abb8e04d3aac271162fac06ff 100644
--- a/Source/platform/graphics/paint/DisplayItemListTest.cpp
+++ b/Source/platform/graphics/paint/DisplayItemListTest.cpp
@@ -57,7 +57,7 @@ private:
 
 class TestDisplayItem : public DisplayItem {
 public:
-    TestDisplayItem(const DisplayItemClientWrapper& client, Type type) : DisplayItem(client, type) { }
+    TestDisplayItem(const TestDisplayItemClient& client, Type type) : DisplayItem(client, type) { }
 
     virtual void replay(GraphicsContext&) override final { ASSERT_NOT_REACHED(); }
     virtual void appendToWebDisplayItemList(WebDisplayItemList*) const override final { ASSERT_NOT_REACHED(); }
@@ -371,8 +371,8 @@ TEST_F(DisplayItemListTest, CachedDisplayItems)
         TestDisplayItem(second, backgroundDrawingType));
     EXPECT_TRUE(displayItemList().clientCacheIsValid(first.displayItemClient()));
     EXPECT_TRUE(displayItemList().clientCacheIsValid(second.displayItemClient()));
-    const SkPicture* firstPicture = displayItemList().displayItems()[0].picture();
-    const SkPicture* secondPicture = displayItemList().displayItems()[1].picture();
+    const SkPicture* firstPicture = static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[0]).picture();
+    const SkPicture* secondPicture = static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[1]).picture();
 
     displayItemList().invalidate(first.displayItemClient());
     EXPECT_FALSE(displayItemList().clientCacheIsValid(first.displayItemClient()));
@@ -386,9 +386,9 @@ TEST_F(DisplayItemListTest, CachedDisplayItems)
         TestDisplayItem(first, backgroundDrawingType),
         TestDisplayItem(second, backgroundDrawingType));
     // The first display item should be updated.
-    EXPECT_NE(firstPicture, displayItemList().displayItems()[0].picture());
+    EXPECT_NE(firstPicture, static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[0]).picture());
     // The second display item should be cached.
-    EXPECT_EQ(secondPicture, displayItemList().displayItems()[1].picture());
+    EXPECT_EQ(secondPicture, static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[1]).picture());
     EXPECT_TRUE(displayItemList().clientCacheIsValid(first.displayItemClient()));
     EXPECT_TRUE(displayItemList().clientCacheIsValid(second.displayItemClient()));
 
@@ -553,12 +553,12 @@ TEST_F(DisplayItemListTest, CachedSubtreeSwapOrder)
 }
 #endif
 
-static bool isDrawing(const DisplayItems::ItemHandle& item)
+static bool isDrawing(const DisplayItem& item)
 {
     return DisplayItem::isDrawingType(item.type());
 }
 
-static bool isCached(const DisplayItems::ItemHandle& item)
+static bool isCached(const DisplayItem& item)
 {
     return DisplayItem::isCachedType(item.type());
 }
@@ -588,8 +588,8 @@ TEST_F(DisplayItemListTest, Scope)
         TestDisplayItem(multicol, backgroundDrawingType),
         TestDisplayItem(content, foregroundDrawingType),
         TestDisplayItem(content, foregroundDrawingType));
-    RefPtr<const SkPicture> picture1 = displayItemList().displayItems()[1].picture();
-    RefPtr<const SkPicture> picture2 = displayItemList().displayItems()[2].picture();
+    RefPtr<const SkPicture> picture1 = static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[1]).picture();
+    RefPtr<const SkPicture> picture2 = static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[2]).picture();
     EXPECT_NE(picture1, picture2);
 
     // Draw again with nothing invalidated.
@@ -612,8 +612,8 @@ TEST_F(DisplayItemListTest, Scope)
         TestDisplayItem(multicol, backgroundDrawingType),
         TestDisplayItem(content, foregroundDrawingType),
         TestDisplayItem(content, foregroundDrawingType));
-    EXPECT_NE(picture1, displayItemList().displayItems()[1].picture());
-    EXPECT_NE(picture2, displayItemList().displayItems()[2].picture());
+    EXPECT_NE(picture1, static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[1]).picture());
+    EXPECT_NE(picture2, static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[2]).picture());
 
     // Now the multicol becomes 3 columns and repaints.
     displayItemList().invalidate(multicol.displayItemClient());
@@ -643,8 +643,8 @@ TEST_F(DisplayItemListTest, Scope)
         TestDisplayItem(content, foregroundDrawingType),
         TestDisplayItem(content, foregroundDrawingType),
         TestDisplayItem(content, foregroundDrawingType));
-    EXPECT_NE(picture1, displayItemList().displayItems()[1].picture());
-    EXPECT_NE(picture2, displayItemList().displayItems()[2].picture());
+    EXPECT_NE(picture1, static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[1]).picture());
+    EXPECT_NE(picture2, static_cast<const DrawingDisplayItem&>(displayItemList().displayItems()[2]).picture());
 }
 
 TEST_F(DisplayItemListTest, OptimizeNoopPairs)