Only create PaintChunks at drawing and foreignLayer boundaries

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

Index: third_party/WebKit/Source/platform/graphics/paint/PaintChunkerTest.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintChunkerTest.cpp b/third_party/WebKit/Source/platform/graphics/paint/PaintChunkerTest.cpp
index 0f55ae596b840d4495e13ba8cff0d75568932107..2c834d0ff8f05c1bca47ca90c6229d891222355c 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintChunkerTest.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintChunkerTest.cpp
@@ -378,5 +378,79 @@ TEST_F(PaintChunkerTest, ChunkIdsSkippingCache) {
                   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