Only create PaintChunks at drawing and foreignLayer boundaries

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

 // Copyright 2015 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 "platform/graphics/paint/PaintChunker.h"
 
 #include "platform/testing/PaintPropertyTestHelpers.h"
 #include "platform/testing/RuntimeEnabledFeaturesTestHelpers.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 360 matching lines @@
   Vector<PaintChunk> chunks = chunker.releasePaintChunks();
   EXPECT_THAT(
       chunks,
       ElementsAre(PaintChunk(0, 2, nullptr, defaultPaintChunkProperties()),
                   PaintChunk(2, 4, nullptr, simpleTransform),
                   PaintChunk(4, 5, nullptr, simpleTransform),
                   PaintChunk(5, 6, nullptr, simpleTransform),
                   PaintChunk(6, 7, nullptr, defaultPaintChunkProperties())));
 }
 
+TEST_F(PaintChunkerTest, NoNonDrawingChunks) {
+  // Non-drawing/foreignLayer items should not create chunks for:
+  //   <xform>, <drawing>, </xform>
+  // with all items in the same property tree state.
+  PaintChunker chunker;
+
+  TestDisplayItem beginTransform(m_client, DisplayItem::kBeginTransform);
+  chunker.updateCurrentPaintChunkProperties(nullptr,
+                                            defaultPaintChunkProperties());
+  chunker.incrementDisplayItemIndex(beginTransform);
+
+  TestDisplayItem drawing(m_client, DisplayItem::kDrawingFirst);
+  chunker.incrementDisplayItemIndex(drawing);
+
+  TestDisplayItem endTransform(m_client, DisplayItem::kEndTransform);
+  chunker.incrementDisplayItemIndex(endTransform);
+
+  EXPECT_THAT(
+      chunker.releasePaintChunks(),
+      ElementsAre(PaintChunk(1, 2, nullptr, defaultPaintChunkProperties())));
+}
+
+TEST_F(PaintChunkerTest, NoNonDrawingChunksWithDifferentProperties) {
+  // Non-drawing/foreignLayer items should not create chunks for:
+  //   <xform>, <drawing>, </xform>
+  // with items in different property tree states.
+  PaintChunker chunker;
+
+  TestDisplayItem beginTransform(m_client, DisplayItem::kBeginTransform);
+  PaintChunkProperties simpleTransform = defaultPaintChunkProperties();
+  simpleTransform.propertyTreeState.setTransform(
+      TransformPaintPropertyNode::create(nullptr,
+                                         TransformationMatrix(0, 1, 2, 3, 4, 5),
+                                         FloatPoint3D(9, 8, 7))
+          .get());
+  chunker.updateCurrentPaintChunkProperties(nullptr, simpleTransform);
+  chunker.incrementDisplayItemIndex(beginTransform);
+
+  TestDisplayItem drawing(m_client, DisplayItem::kDrawingFirst);
+  chunker.updateCurrentPaintChunkProperties(nullptr,
+                                            defaultPaintChunkProperties());
+  chunker.incrementDisplayItemIndex(drawing);
+
+  TestDisplayItem endTransform(m_client, DisplayItem::kEndTransform);
+  chunker.updateCurrentPaintChunkProperties(nullptr, simpleTransform);
+  chunker.incrementDisplayItemIndex(endTransform);
+
+  EXPECT_THAT(
+      chunker.releasePaintChunks(),
+      ElementsAre(PaintChunk(1, 2, nullptr, defaultPaintChunkProperties())));
+}
+
+TEST_F(PaintChunkerTest, NoNonForeignLayerChunks) {
+  // Non-drawing/foreignLayer items should not create chunks for:
+  //   <xform>, <foreignLayer>, </xform>
+  PaintChunker chunker;
+
+  TestDisplayItem beginTransform(m_client, DisplayItem::kBeginTransform);
+  chunker.updateCurrentPaintChunkProperties(nullptr,
+                                            defaultPaintChunkProperties());
+  chunker.incrementDisplayItemIndex(beginTransform);
+
+  TestDisplayItem foreignLayer(m_client, DisplayItem::kForeignLayerCanvas);
+  DisplayItem::Id layerId = foreignLayer.getId();
+  chunker.incrementDisplayItemIndex(foreignLayer);
+
+  TestDisplayItem endTransform(m_client, DisplayItem::kEndTransform);
+  chunker.incrementDisplayItemIndex(endTransform);
+
+  EXPECT_THAT(
+      chunker.releasePaintChunks(),
+      ElementsAre(PaintChunk(1, 2, &layerId, defaultPaintChunkProperties())));
+}
+
 }  // namespace
 }  // namespace blink