Create PaintChunk and begin writing code to build paint chunks.

third_party/WebKit/Source/platform/graphics/paint/DisplayItemListTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "platform/graphics/paint/DisplayItemList.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/paint/CachedDisplayItem.h"
 #include "platform/graphics/paint/ClipPathRecorder.h"
 #include "platform/graphics/paint/ClipRecorder.h"
 #include "platform/graphics/paint/DrawingDisplayItem.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/graphics/paint/SubsequenceRecorder.h"
 #include <gtest/gtest.h>
 
 namespace blink {
 
 class DisplayItemListTest : public ::testing::Test {
 public:
     DisplayItemListTest()
         : m_displayItemList(DisplayItemList::create())
-        , m_originalSlimmingPaintSubsequenceCachingEnabled(RuntimeEnabledFeatures::slimmingPaintSubsequenceCachingEnabled()) { }
+        , m_originalSlimmingPaintSubsequenceCachingEnabled(RuntimeEnabledFeatures::slimmingPaintSubsequenceCachingEnabled())
+        , m_originalSlimmingPaintV2Enabled(RuntimeEnabledFeatures::slimmingPaintV2Enabled()) { }
 
 protected:
     DisplayItemList& displayItemList() { return *m_displayItemList; }
 
 private:
     void TearDown() override
     {
         RuntimeEnabledFeatures::setSlimmingPaintSubsequenceCachingEnabled(m_originalSlimmingPaintSubsequenceCachingEnabled);
+        RuntimeEnabledFeatures::setSlimmingPaintV2Enabled(m_originalSlimmingPaintV2Enabled);
     }
 
     OwnPtr<DisplayItemList> m_displayItemList;
     bool m_originalSlimmingPaintSubsequenceCachingEnabled;
+    bool m_originalSlimmingPaintV2Enabled;
 };
 
 const DisplayItem::Type foregroundDrawingType = static_cast<DisplayItem::Type>(DisplayItem::DrawingPaintPhaseFirst + 4);
 const DisplayItem::Type backgroundDrawingType = DisplayItem::DrawingPaintPhaseFirst;
 const DisplayItem::Type clipType = DisplayItem::ClipFirst;
 const DisplayItem::Type subsequenceType = DisplayItem::SubsequenceNormalFlowAndPositiveZOrder;
 const DisplayItem::Type endSubsequenceType = DisplayItem::subsequenceTypeToEndSubsequenceType(subsequenceType);
 const DisplayItem::Type cachedSubsequenceType = DisplayItem::subsequenceTypeToCachedSubsequenceType(subsequenceType);
 
 class TestDisplayItemClient {
@@ skipping 718 matching lines @@
     }
     drawRect(context, third, backgroundDrawingType, FloatRect(0, 0, 100, 100));
     displayItemList().commitNewDisplayItems();
 
     // Empty clips should have been optimized out.
     EXPECT_DISPLAY_LIST(displayItemList().displayItems(), 2,
         TestDisplayItem(first, backgroundDrawingType),
         TestDisplayItem(third, backgroundDrawingType));
 }
 
+TEST_F(DisplayItemListTest, SmallDisplayItemListHasOnePaintChunk)
+{
+    RuntimeEnabledFeatures::setSlimmingPaintV2Enabled(true);
+    TestDisplayItemClient client("test client");
+
+    GraphicsContext context(&displayItemList());
+    drawRect(context, client, backgroundDrawingType, FloatRect(0, 0, 100, 100));
+
+    displayItemList().commitNewDisplayItems();
+    const auto& paintChunks = displayItemList().paintChunks();
+    ASSERT_EQ(1u, paintChunks.size());
+    EXPECT_EQ(0u, paintChunks[0].beginIndex);
+    EXPECT_EQ(1u, paintChunks[0].endIndex);
+}
+
 } // namespace blink