Slimming Paint phase 2 compositing algorithm plumbing

Source/core/compositing/DisplayListCompositingBuilderTest.cpp

Index: Source/core/compositing/DisplayListCompositingBuilderTest.cpp
diff --git a/Source/core/compositing/DisplayListCompositingBuilderTest.cpp b/Source/core/compositing/DisplayListCompositingBuilderTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..16b93f8354698a99519f75053f777a235e8b72d3
--- /dev/null
+++ b/Source/core/compositing/DisplayListCompositingBuilderTest.cpp
@@ -0,0 +1,96 @@
+// 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 "config.h"
+
+#include "core/layout/LayoutTestHelper.h"
+#include "core/layout/LayoutView.h"
+#include "core/paint/DeprecatedPaintLayer.h"
+#include "platform/graphics/GraphicsLayer.h"
+#include "platform/transforms/TransformTestHelper.h"
+#include "platform/transforms/TransformationMatrix.h"
+#include <gtest/gtest.h>
+
+namespace blink {
+
+class DisplayItemListCompositingBuilderTest : public RenderingTest {

[chrishtr, 2015/08/13 21:33:16]

Make two test class: this one, and one which directly unittests the inputs and
outputs of the builder. Rename this test class accordingly.

[pdr., 2015/08/14 00:10:29]

Done

+public:
+    DisplayItemListCompositingBuilderTest()
+        : m_layoutView(nullptr)
+        , m_originalSlimmingPaintV2Enabled(RuntimeEnabledFeatures::slimmingPaintV2Enabled()) { }
+
+protected:
+    LayoutView& layoutView() { return *m_layoutView; }
+    GraphicsLayer* graphicsLayer() { return layoutView().layer()->graphicsLayerBacking(); }
+
+    void setBodyInnerHTMLWithoutUpdatingLifecycle(const String& htmlContent)
+    {
+        document().body()->setInnerHTML(htmlContent, ASSERT_NO_EXCEPTION);
+    }
+
+private:
+    void SetUp() override
+    {
+        ASSERT_TRUE(RuntimeEnabledFeatures::slimmingPaintEnabled());
+        RuntimeEnabledFeatures::setSlimmingPaintV2Enabled(true);
+
+        RenderingTest::SetUp();
+        enableCompositing();
+
+        m_layoutView = document().view()->layoutView();
+        ASSERT_TRUE(m_layoutView);
+    }
+
+    void TearDown() override
+    {
+        RuntimeEnabledFeatures::setSlimmingPaintV2Enabled(m_originalSlimmingPaintV2Enabled);
+    }
+
+    LayoutView* m_layoutView;
+    bool m_originalSlimmingPaintV2Enabled;
+};
+
+TEST_F(DisplayItemListCompositingBuilderTest, TransformTreeBuildingNoTransforms)
+{
+    setBodyInnerHTML("<style>* { margin: 0; padding: 0;}</style><div>A</div>");

[chrishtr, 2015/08/13 21:33:16]

Document (in RenderingTest.cpp) that setBodyInnerHTML runs a forced layout.

[pdr., 2015/08/14 00:10:29]

Added some comments in LayoutTestHelper.h

+    auto tree = graphicsLayer()->transformTree();
+
+    // There should only be a root transform node.
+    ASSERT_EQ(1u, tree->nodeCount());
+    EXPECT_TRUE(tree->nodeAt(0).isRoot());
+    EXPECT_TRUE(tree->nodeAt(0).matrix.isIdentity());
+}
+
+TEST_F(DisplayItemListCompositingBuilderTest, TransformTreeBuildingMultipleTransforms)
+{
+    setBodyInnerHTML("<style>* { margin: 0; padding: 0;}</style><div style=\"transform: translate3d(2px,3px,4px);\">X</div>");
+    auto tree = graphicsLayer()->transformTree();
+
+    ASSERT_EQ(2u, tree->nodeCount());
+    EXPECT_TRUE(tree->nodeAt(0).isRoot());
+    EXPECT_FALSE(tree->nodeAt(1).isRoot());
+
+    TransformationMatrix matrix;
+    matrix.translate3d(2, 3, 4);
+    EXPECT_TRANSFORMS_ALMOST_EQ(matrix, tree->nodeAt(1).matrix);
+
+    // Add a nested 3d transform.
+    setBodyInnerHTML("<style>* { margin: 0; padding: 0;}</style><div style=\"transform: translate3d(2px,3px,4px);\"><div style=\"transform: translate3d(5px,6px,7px);\">X</div></div>");
+    tree = graphicsLayer()->transformTree();
+
+    ASSERT_EQ(3u, tree->nodeCount());
+    EXPECT_TRUE(tree->nodeAt(0).isRoot());
+    EXPECT_FALSE(tree->nodeAt(1).isRoot());
+    EXPECT_FALSE(tree->nodeAt(2).isRoot());
+
+    matrix.makeIdentity();
+    matrix.translate3d(2, 3, 4);
+    EXPECT_TRANSFORMS_ALMOST_EQ(matrix, tree->nodeAt(1).matrix);
+
+    matrix.makeIdentity();
+    matrix.translate3d(5, 6, 7);
+    EXPECT_TRANSFORMS_ALMOST_EQ(matrix, tree->nodeAt(2).matrix);
+}
+
+} // namespace blink