[cc] Change cc_tests.gyp filenames to Chromium style

BUG=155413

Review URL: https://codereview.chromium.org/11108020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@161642 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3043 insertions, 0 deletions

diff --git a/cc/occlusion_tracker_unittest.cc b/cc/occlusion_tracker_unittest.cc
new file mode 100644
index 0000000..d3385a3
--- /dev/null
+++ b/cc/occlusion_tracker_unittest.cc
@@ -0,0 +1,3043 @@
+// Copyright 2012 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 "CCOcclusionTracker.h"
+
+#include "CCAnimationTestCommon.h"
+#include "CCGeometryTestUtils.h"
+#include "CCLayerAnimationController.h"
+#include "CCLayerImpl.h"
+#include "CCLayerTreeHostCommon.h"
+#include "CCMathUtil.h"
+#include "CCOcclusionTrackerTestCommon.h"
+#include "CCOverdrawMetrics.h"
+#include "CCSingleThreadProxy.h"
+#include "LayerChromium.h"
+#include "Region.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include <public/WebFilterOperation.h>
+#include <public/WebFilterOperations.h>
+#include <public/WebTransformationMatrix.h>
+
+using namespace cc;
+using namespace WebKit;
+using namespace WebKitTests;
+
+namespace {
+
+class TestContentLayerChromium : public LayerChromium {
+public:
+    TestContentLayerChromium()
+        : LayerChromium()
+        , m_overrideOpaqueContentsRect(false)
+    {
+    }
+
+    virtual bool drawsContent() const OVERRIDE { return true; }
+    virtual Region visibleContentOpaqueRegion() const OVERRIDE
+    {
+        if (m_overrideOpaqueContentsRect)
+            return intersection(m_opaqueContentsRect, visibleContentRect());
+        return LayerChromium::visibleContentOpaqueRegion();
+    }
+    void setOpaqueContentsRect(const IntRect& opaqueContentsRect)
+    {
+        m_overrideOpaqueContentsRect = true;
+        m_opaqueContentsRect = opaqueContentsRect;
+    }
+
+private:
+    virtual ~TestContentLayerChromium()
+    {
+    }
+
+    bool m_overrideOpaqueContentsRect;
+    IntRect m_opaqueContentsRect;
+};
+
+class TestContentLayerImpl : public CCLayerImpl {
+public:
+    TestContentLayerImpl(int id)
+        : CCLayerImpl(id)
+        , m_overrideOpaqueContentsRect(false)
+    {
+        setDrawsContent(true);
+    }
+
+    virtual Region visibleContentOpaqueRegion() const OVERRIDE
+    {
+        if (m_overrideOpaqueContentsRect)
+            return intersection(m_opaqueContentsRect, visibleContentRect());
+        return CCLayerImpl::visibleContentOpaqueRegion();
+    }
+    void setOpaqueContentsRect(const IntRect& opaqueContentsRect)
+    {
+        m_overrideOpaqueContentsRect = true;
+        m_opaqueContentsRect = opaqueContentsRect;
+    }
+
+private:
+    bool m_overrideOpaqueContentsRect;
+    IntRect m_opaqueContentsRect;
+};
+
+template<typename LayerType, typename RenderSurfaceType>
+class TestCCOcclusionTrackerWithClip : public TestCCOcclusionTrackerBase<LayerType, RenderSurfaceType> {
+public:
+    TestCCOcclusionTrackerWithClip(IntRect viewportRect, bool recordMetricsForFrame = false)
+        : TestCCOcclusionTrackerBase<LayerType, RenderSurfaceType>(viewportRect, recordMetricsForFrame)
+        , m_overrideLayerClipRect(false)
+    {
+    }
+
+    void setLayerClipRect(const IntRect& rect) { m_overrideLayerClipRect = true; m_layerClipRect = rect;}
+    void useDefaultLayerClipRect() { m_overrideLayerClipRect = false; }
+
+protected:
+    virtual IntRect layerClipRectInTarget(const LayerType* layer) const { return m_overrideLayerClipRect ? m_layerClipRect : CCOcclusionTrackerBase<LayerType, RenderSurfaceType>::layerClipRectInTarget(layer); }
+
+private:
+    bool m_overrideLayerClipRect;
+    IntRect m_layerClipRect;
+};
+
+struct CCOcclusionTrackerTestMainThreadTypes {
+    typedef LayerChromium LayerType;
+    typedef RenderSurfaceChromium RenderSurfaceType;
+    typedef TestContentLayerChromium ContentLayerType;
+    typedef scoped_refptr<LayerChromium> LayerPtrType;
+    typedef scoped_refptr<ContentLayerType> ContentLayerPtrType;
+    typedef CCLayerIterator<LayerChromium, std::vector<scoped_refptr<LayerChromium> >, RenderSurfaceChromium, CCLayerIteratorActions::FrontToBack> LayerIterator;
+    typedef CCOcclusionTracker OcclusionTrackerType;
+
+    static LayerPtrType createLayer()
+    {
+        return LayerChromium::create();
+    }
+    static ContentLayerPtrType createContentLayer() { return make_scoped_refptr(new ContentLayerType()); }
+
+    static LayerPtrType passLayerPtr(ContentLayerPtrType& layer)
+    {
+        return layer.release();
+    }
+
+    static LayerPtrType passLayerPtr(LayerPtrType& layer)
+    {
+        return layer.release();
+    }
+
+    static void destroyLayer(LayerPtrType& layer)
+    {
+        layer = NULL;
+    }
+};
+
+struct CCOcclusionTrackerTestImplThreadTypes {
+    typedef CCLayerImpl LayerType;
+    typedef CCRenderSurface RenderSurfaceType;
+    typedef TestContentLayerImpl ContentLayerType;
+    typedef scoped_ptr<CCLayerImpl> LayerPtrType;
+    typedef scoped_ptr<ContentLayerType> ContentLayerPtrType;
+    typedef CCLayerIterator<CCLayerImpl, std::vector<CCLayerImpl*>, CCRenderSurface, CCLayerIteratorActions::FrontToBack> LayerIterator;
+    typedef CCOcclusionTrackerImpl OcclusionTrackerType;
+
+    static LayerPtrType createLayer() { return CCLayerImpl::create(nextCCLayerImplId++); }
+    static ContentLayerPtrType createContentLayer() { return make_scoped_ptr(new ContentLayerType(nextCCLayerImplId++)); }
+    static int nextCCLayerImplId;
+
+    static LayerPtrType passLayerPtr(LayerPtrType& layer)
+    {
+        return layer.Pass();
+    }
+
+    static LayerPtrType passLayerPtr(ContentLayerPtrType& layer)
+    {
+        return layer.PassAs<LayerType>();
+    }
+
+    static void destroyLayer(LayerPtrType& layer)
+    {
+        layer.reset();
+    }
+};
+
+int CCOcclusionTrackerTestImplThreadTypes::nextCCLayerImplId = 1;
+
+template<typename Types, bool opaqueLayers>
+class CCOcclusionTrackerTest : public testing::Test {
+protected:
+    CCOcclusionTrackerTest()
+        : testing::Test()
+    { }
+
+    virtual void runMyTest() = 0;
+
+    virtual void TearDown()
+    {
+        Types::destroyLayer(m_root);
+        m_renderSurfaceLayerListChromium.clear();
+        m_renderSurfaceLayerListImpl.clear();
+        m_replicaLayers.clear();
+        m_maskLayers.clear();
+        CCLayerTreeHost::setNeedsFilterContext(false);
+    }
+
+    typename Types::ContentLayerType* createRoot(const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        typename Types::ContentLayerPtrType layer(Types::createContentLayer());
+        typename Types::ContentLayerType* layerPtr = layer.get();
+        setProperties(layerPtr, transform, position, bounds);
+
+        ASSERT(!m_root);
+        m_root = Types::passLayerPtr(layer);
+        return layerPtr;
+    }
+
+    typename Types::LayerType* createLayer(typename Types::LayerType* parent, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        typename Types::LayerPtrType layer(Types::createLayer());
+        typename Types::LayerType* layerPtr = layer.get();
+        setProperties(layerPtr, transform, position, bounds);
+        parent->addChild(Types::passLayerPtr(layer));
+        return layerPtr;
+    }
+
+    typename Types::LayerType* createSurface(typename Types::LayerType* parent, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        typename Types::LayerType* layer = createLayer(parent, transform, position, bounds);
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createGrayscaleFilter(0.5));
+        layer->setFilters(filters);
+        return layer;
+    }
+
+    typename Types::ContentLayerType* createDrawingLayer(typename Types::LayerType* parent, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds, bool opaque)
+    {
+        typename Types::ContentLayerPtrType layer(Types::createContentLayer());
+        typename Types::ContentLayerType* layerPtr = layer.get();
+        setProperties(layerPtr, transform, position, bounds);
+
+        if (opaqueLayers)
+            layerPtr->setContentsOpaque(opaque);
+        else {
+            layerPtr->setContentsOpaque(false);
+            if (opaque)
+                layerPtr->setOpaqueContentsRect(IntRect(IntPoint(), bounds));
+            else
+                layerPtr->setOpaqueContentsRect(IntRect());
+        }
+
+        parent->addChild(Types::passLayerPtr(layer));
+        return layerPtr;
+    }
+
+    typename Types::LayerType* createReplicaLayer(typename Types::LayerType* owningLayer, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        typename Types::ContentLayerPtrType layer(Types::createContentLayer());
+        typename Types::ContentLayerType* layerPtr = layer.get();
+        setProperties(layerPtr, transform, position, bounds);
+        setReplica(owningLayer, Types::passLayerPtr(layer));
+        return layerPtr;
+    }
+
+    typename Types::LayerType* createMaskLayer(typename Types::LayerType* owningLayer, const IntSize& bounds)
+    {
+        typename Types::ContentLayerPtrType layer(Types::createContentLayer());
+        typename Types::ContentLayerType* layerPtr = layer.get();
+        setProperties(layerPtr, identityMatrix, FloatPoint(), bounds);
+        setMask(owningLayer, Types::passLayerPtr(layer));
+        return layerPtr;
+    }
+
+    typename Types::ContentLayerType* createDrawingSurface(typename Types::LayerType* parent, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds, bool opaque)
+    {
+        typename Types::ContentLayerType* layer = createDrawingLayer(parent, transform, position, bounds, opaque);
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createGrayscaleFilter(0.5));
+        layer->setFilters(filters);
+        return layer;
+    }
+
+    void calcDrawEtc(TestContentLayerImpl* root)
+    {
+        ASSERT(root == m_root.get());
+        int dummyMaxTextureSize = 512;
+        CCLayerSorter layerSorter;
+
+        ASSERT(!root->renderSurface());
+
+        CCLayerTreeHostCommon::calculateDrawTransforms(root, root->bounds(), 1, &layerSorter, dummyMaxTextureSize, m_renderSurfaceLayerListImpl);
+
+        m_layerIterator = m_layerIteratorBegin = Types::LayerIterator::begin(&m_renderSurfaceLayerListImpl);
+    }
+
+    void calcDrawEtc(TestContentLayerChromium* root)
+    {
+        ASSERT(root == m_root.get());
+        int dummyMaxTextureSize = 512;
+
+        ASSERT(!root->renderSurface());
+
+        CCLayerTreeHostCommon::calculateDrawTransforms(root, root->bounds(), 1, dummyMaxTextureSize, m_renderSurfaceLayerListChromium);
+
+        m_layerIterator = m_layerIteratorBegin = Types::LayerIterator::begin(&m_renderSurfaceLayerListChromium);
+    }
+
+    void enterLayer(typename Types::LayerType* layer, typename Types::OcclusionTrackerType& occlusion)
+    {
+        ASSERT_EQ(layer, *m_layerIterator);
+        ASSERT_TRUE(m_layerIterator.representsItself());
+        occlusion.enterLayer(m_layerIterator);
+    }
+
+    void leaveLayer(typename Types::LayerType* layer, typename Types::OcclusionTrackerType& occlusion)
+    {
+        ASSERT_EQ(layer, *m_layerIterator);
+        ASSERT_TRUE(m_layerIterator.representsItself());
+        occlusion.leaveLayer(m_layerIterator);
+        ++m_layerIterator;
+    }
+
+    void visitLayer(typename Types::LayerType* layer, typename Types::OcclusionTrackerType& occlusion)
+    {
+        enterLayer(layer, occlusion);
+        leaveLayer(layer, occlusion);
+    }
+
+    void enterContributingSurface(typename Types::LayerType* layer, typename Types::OcclusionTrackerType& occlusion)
+    {
+        ASSERT_EQ(layer, *m_layerIterator);
+        ASSERT_TRUE(m_layerIterator.representsTargetRenderSurface());
+        occlusion.enterLayer(m_layerIterator);
+        occlusion.leaveLayer(m_layerIterator);
+        ++m_layerIterator;
+        ASSERT_TRUE(m_layerIterator.representsContributingRenderSurface());
+        occlusion.enterLayer(m_layerIterator);
+    }
+
+    void leaveContributingSurface(typename Types::LayerType* layer, typename Types::OcclusionTrackerType& occlusion)
+    {
+        ASSERT_EQ(layer, *m_layerIterator);
+        ASSERT_TRUE(m_layerIterator.representsContributingRenderSurface());
+        occlusion.leaveLayer(m_layerIterator);
+        ++m_layerIterator;
+    }
+
+    void visitContributingSurface(typename Types::LayerType* layer, typename Types::OcclusionTrackerType& occlusion)
+    {
+        enterContributingSurface(layer, occlusion);
+        leaveContributingSurface(layer, occlusion);
+    }
+
+    void resetLayerIterator()
+    {
+        m_layerIterator = m_layerIteratorBegin;
+    }
+
+    const WebTransformationMatrix identityMatrix;
+
+private:
+    void setBaseProperties(typename Types::LayerType* layer, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        layer->setTransform(transform);
+        layer->setSublayerTransform(WebTransformationMatrix());
+        layer->setAnchorPoint(FloatPoint(0, 0));
+        layer->setPosition(position);
+        layer->setBounds(bounds);
+    }
+
+    void setProperties(LayerChromium* layer, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        setBaseProperties(layer, transform, position, bounds);
+    }
+
+    void setProperties(CCLayerImpl* layer, const WebTransformationMatrix& transform, const FloatPoint& position, const IntSize& bounds)
+    {
+        setBaseProperties(layer, transform, position, bounds);
+
+        layer->setContentBounds(layer->bounds());
+    }
+
+    void setReplica(LayerChromium* owningLayer, scoped_refptr<LayerChromium> layer)
+    {
+        owningLayer->setReplicaLayer(layer.get());
+        m_replicaLayers.push_back(layer);
+    }
+
+    void setReplica(CCLayerImpl* owningLayer, scoped_ptr<CCLayerImpl> layer)
+    {
+        owningLayer->setReplicaLayer(layer.Pass());
+    }
+
+    void setMask(LayerChromium* owningLayer, scoped_refptr<LayerChromium> layer)
+    {
+        owningLayer->setMaskLayer(layer.get());
+        m_maskLayers.push_back(layer);
+    }
+
+    void setMask(CCLayerImpl* owningLayer, scoped_ptr<CCLayerImpl> layer)
+    {
+        owningLayer->setMaskLayer(layer.Pass());
+    }
+
+    // These hold ownership of the layers for the duration of the test.
+    typename Types::LayerPtrType m_root;
+    std::vector<scoped_refptr<LayerChromium> > m_renderSurfaceLayerListChromium;
+    std::vector<CCLayerImpl*> m_renderSurfaceLayerListImpl;
+    typename Types::LayerIterator m_layerIteratorBegin;
+    typename Types::LayerIterator m_layerIterator;
+    typename Types::LayerType* m_lastLayerVisited;
+    std::vector<scoped_refptr<LayerChromium> > m_replicaLayers;
+    std::vector<scoped_refptr<LayerChromium> > m_maskLayers;
+};
+
+#define RUN_TEST_MAIN_THREAD_OPAQUE_LAYERS(ClassName) \
+    class ClassName##MainThreadOpaqueLayers : public ClassName<CCOcclusionTrackerTestMainThreadTypes, true> { \
+    public: \
+        ClassName##MainThreadOpaqueLayers() : ClassName<CCOcclusionTrackerTestMainThreadTypes, true>() { } \
+    }; \
+    TEST_F(ClassName##MainThreadOpaqueLayers, runTest) { runMyTest(); }
+#define RUN_TEST_MAIN_THREAD_OPAQUE_PAINTS(ClassName) \
+    class ClassName##MainThreadOpaquePaints : public ClassName<CCOcclusionTrackerTestMainThreadTypes, false> { \
+    public: \
+        ClassName##MainThreadOpaquePaints() : ClassName<CCOcclusionTrackerTestMainThreadTypes, false>() { } \
+    }; \
+    TEST_F(ClassName##MainThreadOpaquePaints, runTest) { runMyTest(); }
+
+#define RUN_TEST_IMPL_THREAD_OPAQUE_LAYERS(ClassName) \
+    class ClassName##ImplThreadOpaqueLayers : public ClassName<CCOcclusionTrackerTestImplThreadTypes, true> { \
+        DebugScopedSetImplThread impl; \
+    public: \
+        ClassName##ImplThreadOpaqueLayers() : ClassName<CCOcclusionTrackerTestImplThreadTypes, true>() { } \
+    }; \
+    TEST_F(ClassName##ImplThreadOpaqueLayers, runTest) { runMyTest(); }
+#define RUN_TEST_IMPL_THREAD_OPAQUE_PAINTS(ClassName) \
+    class ClassName##ImplThreadOpaquePaints : public ClassName<CCOcclusionTrackerTestImplThreadTypes, false> { \
+        DebugScopedSetImplThread impl; \
+    public: \
+        ClassName##ImplThreadOpaquePaints() : ClassName<CCOcclusionTrackerTestImplThreadTypes, false>() { } \
+    }; \
+    TEST_F(ClassName##ImplThreadOpaquePaints, runTest) { runMyTest(); }
+
+#define ALL_CCOCCLUSIONTRACKER_TEST(ClassName) \
+    RUN_TEST_MAIN_THREAD_OPAQUE_LAYERS(ClassName) \
+    RUN_TEST_MAIN_THREAD_OPAQUE_PAINTS(ClassName) \
+    RUN_TEST_IMPL_THREAD_OPAQUE_LAYERS(ClassName) \
+    RUN_TEST_IMPL_THREAD_OPAQUE_PAINTS(ClassName)
+
+#define MAIN_THREAD_TEST(ClassName) \
+    RUN_TEST_MAIN_THREAD_OPAQUE_LAYERS(ClassName)
+
+#define IMPL_THREAD_TEST(ClassName) \
+    RUN_TEST_IMPL_THREAD_OPAQUE_LAYERS(ClassName)
+
+#define MAIN_AND_IMPL_THREAD_TEST(ClassName) \
+    RUN_TEST_MAIN_THREAD_OPAQUE_LAYERS(ClassName) \
+    RUN_TEST_IMPL_THREAD_OPAQUE_LAYERS(ClassName)
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestIdentityTransforms : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(30, 30), IntSize(500, 500), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 29, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(31, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 31, 70, 70)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 29, 70, 70)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(31, 30, 70, 70)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 31, 70, 70)));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(30, 30, 70, 70)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(29, 30, 1, 70), occlusion.unoccludedContentRect(parent, IntRect(29, 30, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(29, 29, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(29, 29, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(30, 29, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 29, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(31, 29, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(31, 29, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(100, 30, 1, 70), occlusion.unoccludedContentRect(parent, IntRect(31, 30, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(31, 31, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(31, 31, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(30, 100, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 31, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(29, 31, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(29, 31, 70, 70)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestIdentityTransforms);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestRotatedChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix layerTransform;
+        layerTransform.translate(250, 250);
+        layerTransform.rotate(90);
+        layerTransform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, layerTransform, FloatPoint(30, 30), IntSize(500, 500), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 29, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(31, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 31, 70, 70)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 30, 70, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 29, 70, 70)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(31, 30, 70, 70)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 31, 70, 70)));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(30, 30, 70, 70)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(29, 30, 1, 70), occlusion.unoccludedContentRect(parent, IntRect(29, 30, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(29, 29, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(29, 29, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(30, 29, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 29, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(31, 29, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(31, 29, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(100, 30, 1, 70), occlusion.unoccludedContentRect(parent, IntRect(31, 30, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(31, 31, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(31, 31, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(30, 100, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 31, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(29, 31, 70, 70), occlusion.unoccludedContentRect(parent, IntRect(29, 31, 70, 70)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestRotatedChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestTranslatedChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix layerTransform;
+        layerTransform.translate(20, 20);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, layerTransform, FloatPoint(30, 30), IntSize(500, 500), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(50, 50, 50, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(50, 50, 50, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(50, 50, 50, 50)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(49, 50, 50, 50)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(50, 49, 50, 50)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(51, 50, 50, 50)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(50, 51, 50, 50)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(50, 50, 50, 50)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(49, 50, 50, 50)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(50, 49, 50, 50)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(51, 50, 50, 50)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(50, 51, 50, 50)));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(50, 50, 50, 50)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(49, 50, 1, 50), occlusion.unoccludedContentRect(parent, IntRect(49, 50, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(49, 49, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(49, 49, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(50, 49, 50, 1), occlusion.unoccludedContentRect(parent, IntRect(50, 49, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(51, 49, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(51, 49, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(100, 50, 1, 50), occlusion.unoccludedContentRect(parent, IntRect(51, 50, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(51, 51, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(51, 51, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(50, 100, 50, 1), occlusion.unoccludedContentRect(parent, IntRect(50, 51, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(49, 51, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(49, 51, 50, 50)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(50, 50, 50, 50)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(49, 50, 1, 50), occlusion.unoccludedContentRect(parent, IntRect(49, 50, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(49, 49, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(49, 49, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(50, 49, 50, 1), occlusion.unoccludedContentRect(parent, IntRect(50, 49, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(51, 49, 49, 1), occlusion.unoccludedContentRect(parent, IntRect(51, 49, 50, 50)));
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(51, 50, 50, 50)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(51, 51, 50, 50)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(50, 51, 50, 50)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(49, 51, 1, 49), occlusion.unoccludedContentRect(parent, IntRect(49, 51, 50, 50)));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestTranslatedChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestChildInRotatedChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix childTransform;
+        childTransform.translate(250, 250);
+        childTransform.rotate(90);
+        childTransform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* child = this->createLayer(parent, childTransform, FloatPoint(30, 30), IntSize(500, 500));
+        child->setMasksToBounds(true);
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(child, this->identityMatrix, FloatPoint(10, 10), IntSize(500, 500), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(layer, occlusion);
+        this->enterContributingSurface(child, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 40, 70, 60), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(10, 430, 60, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->leaveContributingSurface(child, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 40, 70, 60), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 40, 70, 60), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 39, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(31, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 41, 70, 60)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 39, 70, 60)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(31, 40, 70, 60)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 41, 70, 60)));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+
+        /* Justification for the above occlusion from |layer|:
+                   100
+          +---------------------+                                      +---------------------+
+          |                     |                                      |                     |30  Visible region of |layer|: /////
+          |    30               |           rotate(90)                 |                     |
+          | 30 + ---------------------------------+                    |     +---------------------------------+
+      100 |    |  10            |                 |            ==>     |     |               |10               |
+          |    |10+---------------------------------+                  |  +---------------------------------+  |
+          |    |  |             |                 | |                  |  |  |///////////////|     420      |  |
+          |    |  |             |                 | |                  |  |  |///////////////|60            |  |
+          |    |  |             |                 | |                  |  |  |///////////////|              |  |
+          +----|--|-------------+                 | |                  +--|--|---------------+              |  |
+               |  |                               | |                   20|10|     70                       |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |500                  |  |                              |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |                     |  |                              |10|
+               +--|-------------------------------+ |                     |  +------------------------------|--+
+                  |                                 |                     |                 490             |
+                  +---------------------------------+                     +---------------------------------+
+                                 500                                                     500
+         */
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestChildInRotatedChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestVisitTargetTwoTimes : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix childTransform;
+        childTransform.translate(250, 250);
+        childTransform.rotate(90);
+        childTransform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* child = this->createLayer(parent, childTransform, FloatPoint(30, 30), IntSize(500, 500));
+        child->setMasksToBounds(true);
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(child, this->identityMatrix, FloatPoint(10, 10), IntSize(500, 500), true);
+        // |child2| makes |parent|'s surface get considered by CCOcclusionTracker first, instead of |child|'s. This exercises different code in
+        // leaveToTargetRenderSurface, as the target surface has already been seen.
+        typename Types::ContentLayerType* child2 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(30, 30), IntSize(60, 20), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(-10, -10, 1000, 1000));
+
+        this->visitLayer(child2, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 60, 20), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 30, 60, 20), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitLayer(layer, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(10, 430, 60, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->enterContributingSurface(child, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(10, 430, 60, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // Occlusion in |child2| should get merged with the |child| surface we are leaving now.
+        this->leaveContributingSurface(child, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 30, 70, 70)));
+        EXPECT_RECT_EQ(IntRect(90, 30, 10, 10), occlusion.unoccludedContentRect(parent, IntRect(30, 30, 70, 70)));
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 30, 60, 10)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 30, 60, 10)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 29, 60, 10)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(31, 30, 60, 10)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 31, 60, 10)));
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 39, 70, 60)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(30, 30, 60, 10)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(29, 30, 1, 10), occlusion.unoccludedContentRect(parent, IntRect(29, 30, 60, 10)));
+        EXPECT_RECT_EQ(IntRect(30, 29, 60, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 29, 60, 10)));
+        EXPECT_RECT_EQ(IntRect(90, 30, 1, 10), occlusion.unoccludedContentRect(parent, IntRect(31, 30, 60, 10)));
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(30, 31, 60, 10)).isEmpty());
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(30, 40, 70, 60)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(29, 40, 1, 60), occlusion.unoccludedContentRect(parent, IntRect(29, 40, 70, 60)));
+        // This rect is mostly occluded by |child2|.
+        EXPECT_RECT_EQ(IntRect(90, 39, 10, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 39, 70, 60)));
+        // This rect extends past top/right ends of |child2|.
+        EXPECT_RECT_EQ(IntRect(30, 29, 70, 11), occlusion.unoccludedContentRect(parent, IntRect(30, 29, 70, 70)));
+        // This rect extends past left/right ends of |child2|.
+        EXPECT_RECT_EQ(IntRect(20, 39, 80, 60), occlusion.unoccludedContentRect(parent, IntRect(20, 39, 80, 60)));
+        EXPECT_RECT_EQ(IntRect(100, 40, 1, 60), occlusion.unoccludedContentRect(parent, IntRect(31, 40, 70, 60)));
+        EXPECT_RECT_EQ(IntRect(30, 100, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 41, 70, 60)));
+
+        /* Justification for the above occlusion from |layer|:
+                   100
+          +---------------------+                                      +---------------------+
+          |                     |                                      |                     |30  Visible region of |layer|: /////
+          |    30               |           rotate(90)                 |     30   60         |    |child2|: \\\\\
+          | 30 + ------------+--------------------+                    |  30 +------------+--------------------+
+      100 |    |  10         |  |                 |            ==>     |     |\\\\\\\\\\\\|  |10               |
+          |    |10+----------|----------------------+                  |  +--|\\\\\\\\\\\\|-----------------+  |
+          |    + ------------+  |                 | |                  |  |  +------------+//|     420      |  |
+          |    |  |             |                 | |                  |  |  |///////////////|60            |  |
+          |    |  |             |                 | |                  |  |  |///////////////|              |  |
+          +----|--|-------------+                 | |                  +--|--|---------------+              |  |
+               |  |                               | |                   20|10|     70                       |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |500                  |  |                              |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |                     |  |                              |  |
+               |  |                               | |                     |  |                              |10|
+               +--|-------------------------------+ |                     |  +------------------------------|--+
+                  |                                 |                     |                 490             |
+                  +---------------------------------+                     +---------------------------------+
+                                 500                                                     500
+         */
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestVisitTargetTwoTimes);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceRotatedOffAxis : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix childTransform;
+        childTransform.translate(250, 250);
+        childTransform.rotate(95);
+        childTransform.translate(-250, -250);
+
+        WebTransformationMatrix layerTransform;
+        layerTransform.translate(10, 10);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        typename Types::LayerType* child = this->createLayer(parent, childTransform, FloatPoint(30, 30), IntSize(500, 500));
+        child->setMasksToBounds(true);
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(child, layerTransform, FloatPoint(0, 0), IntSize(500, 500), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        IntRect clippedLayerInChild = CCMathUtil::mapClippedRect(layerTransform, layer->visibleContentRect());
+
+        this->visitLayer(layer, occlusion);
+        this->enterContributingSurface(child, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(clippedLayerInChild, occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(child, clippedLayerInChild));
+        EXPECT_TRUE(occlusion.unoccludedContentRect(child, clippedLayerInChild).isEmpty());
+        clippedLayerInChild.move(-1, 0);
+        EXPECT_FALSE(occlusion.occluded(child, clippedLayerInChild));
+        EXPECT_FALSE(occlusion.unoccludedContentRect(child, clippedLayerInChild).isEmpty());
+        clippedLayerInChild.move(1, 0);
+        clippedLayerInChild.move(1, 0);
+        EXPECT_FALSE(occlusion.occluded(child, clippedLayerInChild));
+        EXPECT_FALSE(occlusion.unoccludedContentRect(child, clippedLayerInChild).isEmpty());
+        clippedLayerInChild.move(-1, 0);
+        clippedLayerInChild.move(0, -1);
+        EXPECT_FALSE(occlusion.occluded(child, clippedLayerInChild));
+        EXPECT_FALSE(occlusion.unoccludedContentRect(child, clippedLayerInChild).isEmpty());
+        clippedLayerInChild.move(0, 1);
+        clippedLayerInChild.move(0, 1);
+        EXPECT_FALSE(occlusion.occluded(child, clippedLayerInChild));
+        EXPECT_FALSE(occlusion.unoccludedContentRect(child, clippedLayerInChild).isEmpty());
+        clippedLayerInChild.move(0, -1);
+
+        this->leaveContributingSurface(child, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(75, 55, 1, 1)));
+        EXPECT_RECT_EQ(IntRect(75, 55, 1, 1), occlusion.unoccludedContentRect(parent, IntRect(75, 55, 1, 1)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestSurfaceRotatedOffAxis);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceWithTwoOpaqueChildren : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix childTransform;
+        childTransform.translate(250, 250);
+        childTransform.rotate(90);
+        childTransform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* child = this->createLayer(parent, childTransform, FloatPoint(30, 30), IntSize(500, 500));
+        child->setMasksToBounds(true);
+        typename Types::ContentLayerType* layer1 = this->createDrawingLayer(child, this->identityMatrix, FloatPoint(10, 10), IntSize(500, 500), true);
+        typename Types::ContentLayerType* layer2 = this->createDrawingLayer(child, this->identityMatrix, FloatPoint(10, 450), IntSize(500, 60), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(layer2, occlusion);
+        this->visitLayer(layer1, occlusion);
+        this->enterContributingSurface(child, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 40, 70, 60), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(10, 430, 60, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(child, IntRect(10, 430, 60, 70)));
+        EXPECT_FALSE(occlusion.occluded(child, IntRect(9, 430, 60, 70)));
+        EXPECT_FALSE(occlusion.occluded(child, IntRect(10, 429, 60, 70)));
+        EXPECT_FALSE(occlusion.occluded(child, IntRect(11, 430, 60, 70)));
+        EXPECT_FALSE(occlusion.occluded(child, IntRect(10, 431, 60, 70)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(child, IntRect(10, 430, 60, 70)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(9, 430, 1, 70), occlusion.unoccludedContentRect(child, IntRect(9, 430, 60, 70)));
+        EXPECT_RECT_EQ(IntRect(10, 429, 60, 1), occlusion.unoccludedContentRect(child, IntRect(10, 429, 60, 70)));
+        EXPECT_RECT_EQ(IntRect(70, 430, 1, 70), occlusion.unoccludedContentRect(child, IntRect(11, 430, 60, 70)));
+        EXPECT_RECT_EQ(IntRect(10, 500, 60, 1), occlusion.unoccludedContentRect(child, IntRect(10, 431, 60, 70)));
+
+        this->leaveContributingSurface(child, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 40, 70, 60), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 40, 70, 60), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 40, 70, 60)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 39, 70, 60)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(30, 40, 70, 60)).isEmpty());
+        EXPECT_RECT_EQ(IntRect(29, 40, 1, 60), occlusion.unoccludedContentRect(parent, IntRect(29, 40, 70, 60)));
+        EXPECT_RECT_EQ(IntRect(30, 39, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 39, 70, 60)));
+        EXPECT_RECT_EQ(IntRect(100, 40, 1, 60), occlusion.unoccludedContentRect(parent, IntRect(31, 40, 70, 60)));
+        EXPECT_RECT_EQ(IntRect(30, 100, 70, 1), occlusion.unoccludedContentRect(parent, IntRect(30, 41, 70, 60)));
+
+        /* Justification for the above occlusion from |layer1| and |layer2|:
+
+           +---------------------+
+           |                     |30  Visible region of |layer1|: /////
+           |                     |    Visible region of |layer2|: \\\\\
+           |     +---------------------------------+
+           |     |               |10               |
+           |  +---------------+-----------------+  |
+           |  |  |\\\\\\\\\\\\|//|     420      |  |
+           |  |  |\\\\\\\\\\\\|//|60            |  |
+           |  |  |\\\\\\\\\\\\|//|              |  |
+           +--|--|------------|--+              |  |
+            20|10|     70     |                 |  |
+              |  |            |                 |  |
+              |  |            |                 |  |
+              |  |            |                 |  |
+              |  |            |                 |  |
+              |  |            |                 |  |
+              |  |            |                 |10|
+              |  +------------|-----------------|--+
+              |               | 490             |
+              +---------------+-----------------+
+                     60               440
+         */
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestSurfaceWithTwoOpaqueChildren);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestOverlappingSurfaceSiblings : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix childTransform;
+        childTransform.translate(250, 250);
+        childTransform.rotate(90);
+        childTransform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* child1 = this->createSurface(parent, childTransform, FloatPoint(30, 30), IntSize(10, 10));
+        typename Types::LayerType* child2 = this->createSurface(parent, childTransform, FloatPoint(20, 40), IntSize(10, 10));
+        typename Types::ContentLayerType* layer1 = this->createDrawingLayer(child1, this->identityMatrix, FloatPoint(-10, -10), IntSize(510, 510), true);
+        typename Types::ContentLayerType* layer2 = this->createDrawingLayer(child2, this->identityMatrix, FloatPoint(-10, -10), IntSize(510, 510), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(-20, -20, 1000, 1000));
+
+        this->visitLayer(layer2, occlusion);
+        this->enterContributingSurface(child2, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(20, 30, 80, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(-10, 420, 70, 80), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-10, 420, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-11, 420, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-10, 419, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-10, 420, 71, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-10, 420, 70, 81)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-10, 420, 70, 80)));
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-11, 420, 70, 80)));
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-10, 419, 70, 80)));
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-10, 420, 71, 80)));
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-10, 420, 70, 81)));
+        occlusion.setLayerClipRect(IntRect(-20, -20, 1000, 1000));
+
+        // There is nothing above child2's surface in the z-order.
+        EXPECT_RECT_EQ(IntRect(-10, 420, 70, 80), occlusion.unoccludedContributingSurfaceContentRect(child2, false, IntRect(-10, 420, 70, 80)));
+
+        this->leaveContributingSurface(child2, occlusion);
+        this->visitLayer(layer1, occlusion);
+        this->enterContributingSurface(child1, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(20, 20, 80, 80), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(-10, 430, 80, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(child1, IntRect(-10, 430, 80, 70)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(-11, 430, 80, 70)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(-10, 429, 80, 70)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(-10, 430, 81, 70)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(-10, 430, 80, 71)));
+
+        // child2's contents will occlude child1 below it.
+        EXPECT_RECT_EQ(IntRect(-10, 430, 10, 70), occlusion.unoccludedContributingSurfaceContentRect(child1, false, IntRect(-10, 430, 80, 70)));
+
+        this->leaveContributingSurface(child1, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(20, 20, 80, 80), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(20, 20, 80, 80), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(20, 20, 80, 80)));
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(30, 20, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(29, 20, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(30, 19, 70, 80)));
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(20, 30, 80, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(19, 30, 80, 70)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(20, 29, 80, 70)));
+
+        /* Justification for the above occlusion:
+                   100
+          +---------------------+
+          |    20               |       layer1
+          |  30+ ---------------------------------+
+      100 |  30|                |     layer2      |
+          |20+----------------------------------+ |
+          |  | |                |               | |
+          |  | |                |               | |
+          |  | |                |               | |
+          +--|-|----------------+               | |
+             | |                                | | 510
+             | |                                | |
+             | |                                | |
+             | |                                | |
+             | |                                | |
+             | |                                | |
+             | |                                | |
+             | +--------------------------------|-+
+             |                                  |
+             +----------------------------------+
+                             510
+         */
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestOverlappingSurfaceSiblings);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestOverlappingSurfaceSiblingsWithTwoTransforms : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix child1Transform;
+        child1Transform.translate(250, 250);
+        child1Transform.rotate(-90);
+        child1Transform.translate(-250, -250);
+
+        WebTransformationMatrix child2Transform;
+        child2Transform.translate(250, 250);
+        child2Transform.rotate(90);
+        child2Transform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* child1 = this->createSurface(parent, child1Transform, FloatPoint(30, 20), IntSize(10, 10));
+        typename Types::LayerType* child2 = this->createDrawingSurface(parent, child2Transform, FloatPoint(20, 40), IntSize(10, 10), false);
+        typename Types::ContentLayerType* layer1 = this->createDrawingLayer(child1, this->identityMatrix, FloatPoint(-10, -20), IntSize(510, 510), true);
+        typename Types::ContentLayerType* layer2 = this->createDrawingLayer(child2, this->identityMatrix, FloatPoint(-10, -10), IntSize(510, 510), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(-30, -30, 1000, 1000));
+
+        this->visitLayer(layer2, occlusion);
+        this->enterLayer(child2, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(20, 30, 80, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(-10, 420, 70, 80), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(child2, IntRect(-10, 420, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-11, 420, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-10, 419, 70, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-10, 420, 71, 80)));
+        EXPECT_FALSE(occlusion.occluded(child2, IntRect(-10, 420, 70, 81)));
+
+        this->leaveLayer(child2, occlusion);
+        this->enterContributingSurface(child2, occlusion);
+
+        // There is nothing above child2's surface in the z-order.
+        EXPECT_RECT_EQ(IntRect(-10, 420, 70, 80), occlusion.unoccludedContributingSurfaceContentRect(child2, false, IntRect(-10, 420, 70, 80)));
+
+        this->leaveContributingSurface(child2, occlusion);
+        this->visitLayer(layer1, occlusion);
+        this->enterContributingSurface(child1, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(10, 20, 90, 80), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(420, -20, 80, 90), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(child1, IntRect(420, -20, 80, 90)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(419, -20, 80, 90)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(420, -21, 80, 90)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(420, -19, 80, 90)));
+        EXPECT_FALSE(occlusion.occluded(child1, IntRect(421, -20, 80, 90)));
+
+        // child2's contents will occlude child1 below it.
+        EXPECT_RECT_EQ(IntRect(420, -20, 80, 90), occlusion.unoccludedContributingSurfaceContentRect(child1, false, IntRect(420, -20, 80, 90)));
+        EXPECT_RECT_EQ(IntRect(490, -10, 10, 80), occlusion.unoccludedContributingSurfaceContentRect(child1, false, IntRect(420, -10, 80, 90)));
+        EXPECT_RECT_EQ(IntRect(420, -20, 70, 10), occlusion.unoccludedContributingSurfaceContentRect(child1, false, IntRect(420, -20, 70, 90)));
+
+        this->leaveContributingSurface(child1, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(10, 20, 90, 80), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(10, 20, 90, 80), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(10, 20, 90, 80)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(9, 20, 90, 80)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(10, 19, 90, 80)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(11, 20, 90, 80)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(10, 21, 90, 80)));
+
+        /* Justification for the above occlusion:
+                      100
+            +---------------------+
+            |20                   |       layer1
+           10+----------------------------------+
+        100 || 30                 |     layer2  |
+            |20+----------------------------------+
+            || |                  |             | |
+            || |                  |             | |
+            || |                  |             | |
+            +|-|------------------+             | |
+             | |                                | | 510
+             | |                            510 | |
+             | |                                | |
+             | |                                | |
+             | |                                | |
+             | |                                | |
+             | |                520             | |
+             +----------------------------------+ |
+               |                                  |
+               +----------------------------------+
+                               510
+         */
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestOverlappingSurfaceSiblingsWithTwoTransforms);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestFilters : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix layerTransform;
+        layerTransform.translate(250, 250);
+        layerTransform.rotate(90);
+        layerTransform.translate(-250, -250);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::ContentLayerType* blurLayer = this->createDrawingLayer(parent, layerTransform, FloatPoint(30, 30), IntSize(500, 500), true);
+        typename Types::ContentLayerType* opaqueLayer = this->createDrawingLayer(parent, layerTransform, FloatPoint(30, 30), IntSize(500, 500), true);
+        typename Types::ContentLayerType* opacityLayer = this->createDrawingLayer(parent, layerTransform, FloatPoint(30, 30), IntSize(500, 500), true);
+
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(10));
+        blurLayer->setFilters(filters);
+
+        filters.clear();
+        filters.append(WebFilterOperation::createGrayscaleFilter(0.5));
+        opaqueLayer->setFilters(filters);
+
+        filters.clear();
+        filters.append(WebFilterOperation::createOpacityFilter(0.5));
+        opacityLayer->setFilters(filters);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // Opacity layer won't contribute to occlusion.
+        this->visitLayer(opacityLayer, occlusion);
+        this->enterContributingSurface(opacityLayer, occlusion);
+
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().isEmpty());
+        EXPECT_TRUE(occlusion.occlusionInTargetSurface().isEmpty());
+
+        // And has nothing to contribute to its parent surface.
+        this->leaveContributingSurface(opacityLayer, occlusion);
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().isEmpty());
+        EXPECT_TRUE(occlusion.occlusionInTargetSurface().isEmpty());
+
+        // Opaque layer will contribute to occlusion.
+        this->visitLayer(opaqueLayer, occlusion);
+        this->enterContributingSurface(opaqueLayer, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 430, 70, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // And it gets translated to the parent surface.
+        this->leaveContributingSurface(opaqueLayer, occlusion);
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // The blur layer needs to throw away any occlusion from outside its subtree.
+        this->enterLayer(blurLayer, occlusion);
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().isEmpty());
+        EXPECT_TRUE(occlusion.occlusionInTargetSurface().isEmpty());
+
+        // And it won't contribute to occlusion.
+        this->leaveLayer(blurLayer, occlusion);
+        this->enterContributingSurface(blurLayer, occlusion);
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().isEmpty());
+        EXPECT_TRUE(occlusion.occlusionInTargetSurface().isEmpty());
+
+        // But the opaque layer's occlusion is preserved on the parent. 
+        this->leaveContributingSurface(blurLayer, occlusion);
+        this->enterLayer(parent, occlusion);
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(30, 30, 70, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestFilters);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestReplicaDoesOcclude : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(50, 50), true);
+        this->createReplicaLayer(surface, this->identityMatrix, FloatPoint(50, 50), IntSize());
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 100, 50, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitContributingSurface(surface, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        // The surface and replica should both be occluding the parent.
+        EXPECT_RECT_EQ(IntRect(0, 100, 100, 100), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestReplicaDoesOcclude);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestReplicaWithClipping : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 170));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(50, 50), true);
+        this->createReplicaLayer(surface, this->identityMatrix, FloatPoint(50, 50), IntSize());
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 100, 50, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitContributingSurface(surface, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        // The surface and replica should both be occluding the parent.
+        EXPECT_RECT_EQ(IntRect(0, 100, 100, 70), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestReplicaWithClipping);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestReplicaWithMask : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(50, 50), true);
+        typename Types::LayerType* replica = this->createReplicaLayer(surface, this->identityMatrix, FloatPoint(50, 50), IntSize());
+        this->createMaskLayer(replica, IntSize(10, 10));
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 100, 50, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitContributingSurface(surface, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        // The replica should not be occluding the parent, since it has a mask applied to it.
+        EXPECT_RECT_EQ(IntRect(0, 100, 50, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestReplicaWithMask);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLayerClipRectOutsideChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(200, 100, 100, 100));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(200, 100, 100, 100)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(200, 100, 100, 100)));
+        occlusion.setLayerClipRect(IntRect(200, 100, 100, 100));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_RECT_EQ(IntRect(200, 100, 100, 100), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestLayerClipRectOutsideChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestViewportRectOutsideChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(200, 100, 100, 100));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(200, 100, 100, 100)));
+
+        occlusion.useDefaultLayerClipRect();
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(200, 100, 100, 100)));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_RECT_EQ(IntRect(200, 100, 100, 100), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestViewportRectOutsideChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLayerClipRectOverChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(100, 100, 100, 100));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)).isEmpty());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestLayerClipRectOverChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestViewportRectOverChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(100, 100, 100, 100));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)).isEmpty());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestViewportRectOverChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLayerClipRectPartlyOverChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(50, 50, 200, 200));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_RECT_EQ(IntRect(50, 50, 200, 200), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+        EXPECT_RECT_EQ(IntRect(200, 50, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 100)));
+        EXPECT_RECT_EQ(IntRect(200, 100, 50, 100), occlusion.unoccludedContentRect(parent, IntRect(0, 100, 300, 100)));
+        EXPECT_RECT_EQ(IntRect(200, 100, 50, 100), occlusion.unoccludedContentRect(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(100, 200, 100, 50), occlusion.unoccludedContentRect(parent, IntRect(100, 200, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestLayerClipRectPartlyOverChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestViewportRectPartlyOverChild : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(50, 50, 200, 200));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_RECT_EQ(IntRect(50, 50, 200, 200), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+        EXPECT_RECT_EQ(IntRect(200, 50, 50, 50), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 100)));
+        EXPECT_RECT_EQ(IntRect(200, 100, 50, 100), occlusion.unoccludedContentRect(parent, IntRect(0, 100, 300, 100)));
+        EXPECT_RECT_EQ(IntRect(200, 100, 50, 100), occlusion.unoccludedContentRect(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(100, 200, 100, 50), occlusion.unoccludedContentRect(parent, IntRect(100, 200, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestViewportRectPartlyOverChild);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLayerClipRectOverNothing : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(500, 500, 100, 100));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 100)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 100, 300, 100)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(200, 100, 100, 100)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(100, 200, 100, 100)).isEmpty());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestLayerClipRectOverNothing);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestViewportRectOverNothing : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(500, 500, 100, 100));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 100, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 0, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(0, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 200, 100, 100)));
+        EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 100)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(0, 100, 300, 100)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(200, 100, 100, 100)).isEmpty());
+        EXPECT_TRUE(occlusion.unoccludedContentRect(parent, IntRect(100, 200, 100, 100)).isEmpty());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestViewportRectOverNothing);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLayerClipRectForLayerOffOrigin : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        this->enterLayer(layer, occlusion);
+
+        // This layer is translated when drawn into its target. So if the clip rect given from the target surface
+        // is not in that target space, then after translating these query rects into the target, they will fall outside
+        // the clip and be considered occluded.
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestLayerClipRectForLayerOffOrigin);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestOpaqueContentsRegionEmpty : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 200), false);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 0, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(0, 100, 100, 100)));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(100, 100, 100, 100)));
+
+        // Occluded since its outside the surface bounds.
+        EXPECT_TRUE(occlusion.occluded(layer, IntRect(200, 100, 100, 100)));
+
+        // Test without any clip rect.
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+        EXPECT_FALSE(occlusion.occluded(layer, IntRect(200, 100, 100, 100)));
+        occlusion.useDefaultLayerClipRect();
+
+        this->leaveLayer(layer, occlusion);
+        this->visitContributingSurface(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().bounds().isEmpty());
+        EXPECT_EQ(0u, occlusion.occlusionInScreenSpace().rects().size());
+    }
+};
+
+MAIN_AND_IMPL_THREAD_TEST(CCOcclusionTrackerTestOpaqueContentsRegionEmpty);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestOpaqueContentsRegionNonEmpty : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(100, 100), IntSize(200, 200), false);
+        this->calcDrawEtc(parent);
+
+        {
+            TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+            layer->setOpaqueContentsRect(IntRect(0, 0, 100, 100));
+
+            this->resetLayerIterator();
+            this->visitLayer(layer, occlusion);
+            this->enterLayer(parent, occlusion);
+
+            EXPECT_RECT_EQ(IntRect(100, 100, 100, 100), occlusion.occlusionInScreenSpace().bounds());
+            EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+            EXPECT_TRUE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+        }
+
+        {
+            TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+            layer->setOpaqueContentsRect(IntRect(20, 20, 180, 180));
+
+            this->resetLayerIterator();
+            this->visitLayer(layer, occlusion);
+            this->enterLayer(parent, occlusion);
+
+            EXPECT_RECT_EQ(IntRect(120, 120, 180, 180), occlusion.occlusionInScreenSpace().bounds());
+            EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+            EXPECT_TRUE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+        }
+
+        {
+            TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+            layer->setOpaqueContentsRect(IntRect(150, 150, 100, 100));
+
+            this->resetLayerIterator();
+            this->visitLayer(layer, occlusion);
+            this->enterLayer(parent, occlusion);
+
+            EXPECT_RECT_EQ(IntRect(250, 250, 50, 50), occlusion.occlusionInScreenSpace().bounds());
+            EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(0, 100, 100, 100)));
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(100, 100, 100, 100)));
+            EXPECT_FALSE(occlusion.occluded(parent, IntRect(200, 200, 100, 100)));
+        }
+    }
+};
+
+MAIN_AND_IMPL_THREAD_TEST(CCOcclusionTrackerTestOpaqueContentsRegionNonEmpty);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTest3dTransform : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix transform;
+        transform.rotate3d(0, 30, 0);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::LayerType* container = this->createLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(container, transform, FloatPoint(100, 100), IntSize(200, 200), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        this->enterLayer(layer, occlusion);
+
+        // The layer is rotated in 3d but without preserving 3d, so it only gets resized.
+        EXPECT_RECT_EQ(IntRect(0, 0, 200, 200), occlusion.unoccludedContentRect(layer, IntRect(0, 0, 200, 200)));
+    }
+};
+
+MAIN_AND_IMPL_THREAD_TEST(CCOcclusionTrackerTest3dTransform);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestUnsorted3dLayers : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        // Currently, the main thread layer iterator does not iterate over 3d items in
+        // sorted order, because layer sorting is not performed on the main thread.
+        // Because of this, the occlusion tracker cannot assume that a 3d layer occludes
+        // other layers that have not yet been iterated over. For now, the expected
+        // behavior is that a 3d layer simply does not add any occlusion to the occlusion
+        // tracker.
+
+        WebTransformationMatrix translationToFront;
+        translationToFront.translate3d(0, 0, -10);
+        WebTransformationMatrix translationToBack;
+        translationToFront.translate3d(0, 0, -100);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* child1 = this->createDrawingLayer(parent, translationToBack, FloatPoint(0, 0), IntSize(100, 100), true);
+        typename Types::ContentLayerType* child2 = this->createDrawingLayer(parent, translationToFront, FloatPoint(50, 50), IntSize(100, 100), true);
+        parent->setPreserves3D(true);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        this->visitLayer(child2, occlusion);
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().isEmpty());
+        EXPECT_TRUE(occlusion.occlusionInTargetSurface().isEmpty());
+
+        this->visitLayer(child1, occlusion);
+        EXPECT_TRUE(occlusion.occlusionInScreenSpace().isEmpty());
+        EXPECT_TRUE(occlusion.occlusionInTargetSurface().isEmpty());
+    }
+};
+
+// This test will have different layer ordering on the impl thread; the test will only work on the main thread.
+MAIN_THREAD_TEST(CCOcclusionTrackerTestUnsorted3dLayers);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestPerspectiveTransform : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix transform;
+        transform.translate(150, 150);
+        transform.applyPerspective(400);
+        transform.rotate3d(1, 0, 0, -30);
+        transform.translate(-150, -150);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::LayerType* container = this->createLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(container, transform, FloatPoint(100, 100), IntSize(200, 200), true);
+        container->setPreserves3D(true);
+        layer->setPreserves3D(true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        this->enterLayer(layer, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 200, 200), occlusion.unoccludedContentRect(layer, IntRect(0, 0, 200, 200)));
+    }
+};
+
+// This test requires accumulating occlusion of 3d layers, which are skipped by the occlusion tracker on the main thread. So this test should run on the impl thread.
+IMPL_THREAD_TEST(CCOcclusionTrackerTestPerspectiveTransform);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestPerspectiveTransformBehindCamera : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        // This test is based on the platform/chromium/compositing/3d-corners.html layout test.
+        WebTransformationMatrix transform;
+        transform.translate(250, 50);
+        transform.applyPerspective(10);
+        transform.translate(-250, -50);
+        transform.translate(250, 50);
+        transform.rotate3d(1, 0, 0, -167);
+        transform.translate(-250, -50);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(500, 100));
+        typename Types::LayerType* container = this->createLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(500, 500));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(container, transform, FloatPoint(0, 0), IntSize(500, 500), true);
+        container->setPreserves3D(true);
+        layer->setPreserves3D(true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        this->enterLayer(layer, occlusion);
+
+        // The bottom 11 pixel rows of this layer remain visible inside the container, after translation to the target surface. When translated back,
+        // this will include many more pixels but must include at least the bottom 11 rows.
+        EXPECT_TRUE(occlusion.unoccludedContentRect(layer, IntRect(0, 0, 500, 500)).contains(IntRect(0, 489, 500, 11)));
+    }
+};
+
+// This test requires accumulating occlusion of 3d layers, which are skipped by the occlusion tracker on the main thread. So this test should run on the impl thread.
+IMPL_THREAD_TEST(CCOcclusionTrackerTestPerspectiveTransformBehindCamera);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLayerBehindCameraDoesNotOcclude : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix transform;
+        transform.translate(50, 50);
+        transform.applyPerspective(100);
+        transform.translate3d(0, 0, 110);
+        transform.translate(-50, -50);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, transform, FloatPoint(0, 0), IntSize(100, 100), true);
+        parent->setPreserves3D(true);
+        layer->setPreserves3D(true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        // The |layer| is entirely behind the camera and should not occlude.
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+        EXPECT_EQ(0u, occlusion.occlusionInTargetSurface().rects().size());
+        EXPECT_EQ(0u, occlusion.occlusionInScreenSpace().rects().size());
+    }
+};
+
+// This test requires accumulating occlusion of 3d layers, which are skipped by the occlusion tracker on the main thread. So this test should run on the impl thread.
+IMPL_THREAD_TEST(CCOcclusionTrackerTestLayerBehindCameraDoesNotOcclude);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestLargePixelsOccludeInsideClipRect : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix transform;
+        transform.translate(50, 50);
+        transform.applyPerspective(100);
+        transform.translate3d(0, 0, 99);
+        transform.translate(-50, -50);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100));
+        parent->setMasksToBounds(true);
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, transform, FloatPoint(0, 0), IntSize(100, 100), true);
+        parent->setPreserves3D(true);
+        layer->setPreserves3D(true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        // This is very close to the camera, so pixels in its visibleContentRect will actually go outside of the layer's clipRect.
+        // Ensure that those pixels don't occlude things outside the clipRect.
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+    }
+};
+
+// This test requires accumulating occlusion of 3d layers, which are skipped by the occlusion tracker on the main thread. So this test should run on the impl thread.
+IMPL_THREAD_TEST(CCOcclusionTrackerTestLargePixelsOccludeInsideClipRect);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestAnimationOpacity1OnMainThread : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), true);
+        typename Types::ContentLayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), true);
+        typename Types::ContentLayerType* surfaceChild = this->createDrawingLayer(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 300), true);
+        typename Types::ContentLayerType* surfaceChild2 = this->createDrawingLayer(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 300), true);
+        typename Types::ContentLayerType* parent2 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), false);
+        typename Types::ContentLayerType* topmost = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(250, 0), IntSize(50, 300), true);
+
+        addOpacityTransitionToController(*layer->layerAnimationController(), 10, 0, 1, false);
+        addOpacityTransitionToController(*surface->layerAnimationController(), 10, 0, 1, false);
+        this->calcDrawEtc(parent);
+
+        EXPECT_TRUE(layer->drawOpacityIsAnimating());
+        EXPECT_FALSE(surface->drawOpacityIsAnimating());
+        EXPECT_TRUE(surface->renderSurface()->drawOpacityIsAnimating());
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(topmost, occlusion);
+        this->enterLayer(parent2, occlusion);
+        // This occlusion will affect all surfaces.
+        EXPECT_RECT_EQ(IntRect(0, 0, 250, 300), occlusion.unoccludedContentRect(parent2, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(parent2, occlusion);
+
+        this->visitLayer(surfaceChild2, occlusion);
+        this->enterLayer(surfaceChild, occlusion);
+        EXPECT_RECT_EQ(IntRect(100, 0, 100, 300), occlusion.unoccludedContentRect(surfaceChild, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(surfaceChild, occlusion);
+        this->enterLayer(surface, occlusion);
+        EXPECT_RECT_EQ(IntRect(200, 0, 50, 300), occlusion.unoccludedContentRect(surface, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(surface, occlusion);
+
+        this->enterContributingSurface(surface, occlusion);
+        // Occlusion within the surface is lost when leaving the animating surface.
+        EXPECT_RECT_EQ(IntRect(0, 0, 250, 300), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 300, 300)));
+        this->leaveContributingSurface(surface, occlusion);
+
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        // Occlusion is not added for the animating |layer|.
+        EXPECT_RECT_EQ(IntRect(0, 0, 250, 300), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+    }
+};
+
+MAIN_THREAD_TEST(CCOcclusionTrackerTestAnimationOpacity1OnMainThread);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestAnimationOpacity0OnMainThread : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), true);
+        typename Types::ContentLayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), true);
+        typename Types::ContentLayerType* surfaceChild = this->createDrawingLayer(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 300), true);
+        typename Types::ContentLayerType* surfaceChild2 = this->createDrawingLayer(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 300), true);
+        typename Types::ContentLayerType* parent2 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), false);
+        typename Types::ContentLayerType* topmost = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(250, 0), IntSize(50, 300), true);
+
+        addOpacityTransitionToController(*layer->layerAnimationController(), 10, 1, 0, false);
+        addOpacityTransitionToController(*surface->layerAnimationController(), 10, 1, 0, false);
+        this->calcDrawEtc(parent);
+
+        EXPECT_TRUE(layer->drawOpacityIsAnimating());
+        EXPECT_FALSE(surface->drawOpacityIsAnimating());
+        EXPECT_TRUE(surface->renderSurface()->drawOpacityIsAnimating());
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(topmost, occlusion);
+        this->enterLayer(parent2, occlusion);
+        // This occlusion will affect all surfaces.
+        EXPECT_RECT_EQ(IntRect(0, 0, 250, 300), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(parent2, occlusion);
+
+        this->visitLayer(surfaceChild2, occlusion);
+        this->enterLayer(surfaceChild, occlusion);
+        EXPECT_RECT_EQ(IntRect(100, 0, 100, 300), occlusion.unoccludedContentRect(surfaceChild, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(surfaceChild, occlusion);
+        this->enterLayer(surface, occlusion);
+        EXPECT_RECT_EQ(IntRect(200, 0, 50, 300), occlusion.unoccludedContentRect(surface, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(surface, occlusion);
+
+        this->enterContributingSurface(surface, occlusion);
+        // Occlusion within the surface is lost when leaving the animating surface.
+        EXPECT_RECT_EQ(IntRect(0, 0, 250, 300), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 300, 300)));
+        this->leaveContributingSurface(surface, occlusion);
+
+        this->visitLayer(layer, occlusion);
+        this->enterLayer(parent, occlusion);
+
+        // Occlusion is not added for the animating |layer|.
+        EXPECT_RECT_EQ(IntRect(0, 0, 250, 300), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+    }
+};
+
+MAIN_THREAD_TEST(CCOcclusionTrackerTestAnimationOpacity0OnMainThread);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestAnimationTranslateOnMainThread : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        typename Types::ContentLayerType* layer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), true);
+        typename Types::ContentLayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300), true);
+        typename Types::ContentLayerType* surfaceChild = this->createDrawingLayer(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(200, 300), true);
+        typename Types::ContentLayerType* surfaceChild2 = this->createDrawingLayer(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 300), true);
+        typename Types::ContentLayerType* surface2 = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(50, 300), true);
+
+        addAnimatedTransformToController(*layer->layerAnimationController(), 10, 30, 0);
+        addAnimatedTransformToController(*surface->layerAnimationController(), 10, 30, 0);
+        addAnimatedTransformToController(*surfaceChild->layerAnimationController(), 10, 30, 0);
+        this->calcDrawEtc(parent);
+
+        EXPECT_TRUE(layer->drawTransformIsAnimating());
+        EXPECT_TRUE(layer->screenSpaceTransformIsAnimating());
+        EXPECT_TRUE(surface->renderSurface()->targetSurfaceTransformsAreAnimating());
+        EXPECT_TRUE(surface->renderSurface()->screenSpaceTransformsAreAnimating());
+        // The surface owning layer doesn't animate against its own surface.
+        EXPECT_FALSE(surface->drawTransformIsAnimating());
+        EXPECT_TRUE(surface->screenSpaceTransformIsAnimating());
+        EXPECT_TRUE(surfaceChild->drawTransformIsAnimating());
+        EXPECT_TRUE(surfaceChild->screenSpaceTransformIsAnimating());
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(surface2, occlusion);
+        this->enterContributingSurface(surface2, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 300), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+
+        this->leaveContributingSurface(surface2, occlusion);
+        this->enterLayer(surfaceChild2, occlusion);
+
+        // surfaceChild2 is moving in screen space but not relative to its target, so occlusion should happen in its target space only.
+        // It also means that things occluding in screen space (e.g. surface2) cannot occlude this layer.
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 300), occlusion.unoccludedContentRect(surfaceChild2, IntRect(0, 0, 100, 300)));
+        EXPECT_FALSE(occlusion.occluded(surfaceChild, IntRect(0, 0, 50, 300)));
+
+        this->leaveLayer(surfaceChild2, occlusion);
+        this->enterLayer(surfaceChild, occlusion);
+        EXPECT_FALSE(occlusion.occluded(surfaceChild, IntRect(0, 0, 100, 300)));
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 300), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 300), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+        EXPECT_RECT_EQ(IntRect(100, 0, 200, 300), occlusion.unoccludedContentRect(surface, IntRect(0, 0, 300, 300)));
+
+        // The surfaceChild is occluded by the surfaceChild2, but is moving relative its target and the screen, so it
+        // can't be occluded.
+        EXPECT_RECT_EQ(IntRect(0, 0, 200, 300), occlusion.unoccludedContentRect(surfaceChild, IntRect(0, 0, 200, 300)));
+        EXPECT_FALSE(occlusion.occluded(surfaceChild, IntRect(0, 0, 50, 300)));
+
+        this->leaveLayer(surfaceChild, occlusion);
+        this->enterLayer(surface, occlusion);
+        // The surfaceChild is moving in screen space but not relative to its target, so occlusion should happen in its target space only.
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 300), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 300), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+        EXPECT_RECT_EQ(IntRect(100, 0, 200, 300), occlusion.unoccludedContentRect(surface, IntRect(0, 0, 300, 300)));
+
+        this->leaveLayer(surface, occlusion);
+        // The surface's owning layer is moving in screen space but not relative to its target, so occlusion should happen in its target space only.
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 300), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 300), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 0, 0), occlusion.unoccludedContentRect(surface, IntRect(0, 0, 300, 300)));
+
+        this->enterContributingSurface(surface, occlusion);
+        // The contributing |surface| is animating so it can't be occluded.
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 300), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 300, 300)));
+        this->leaveContributingSurface(surface, occlusion);
+
+        this->enterLayer(layer, occlusion);
+        // The |surface| is moving in the screen and in its target, so all occlusion within the surface is lost when leaving it.
+        EXPECT_RECT_EQ(IntRect(50, 0, 250, 300), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+        this->leaveLayer(layer, occlusion);
+
+        this->enterLayer(parent, occlusion);
+        // The |layer| is animating in the screen and in its target, so no occlusion is added.
+        EXPECT_RECT_EQ(IntRect(50, 0, 250, 300), occlusion.unoccludedContentRect(parent, IntRect(0, 0, 300, 300)));
+    }
+};
+
+MAIN_THREAD_TEST(CCOcclusionTrackerTestAnimationTranslateOnMainThread);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceOcclusionTranslatesToParent : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix surfaceTransform;
+        surfaceTransform.translate(300, 300);
+        surfaceTransform.scale(2);
+        surfaceTransform.translate(-150, -150);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(500, 500));
+        typename Types::ContentLayerType* surface = this->createDrawingSurface(parent, surfaceTransform, FloatPoint(0, 0), IntSize(300, 300), false);
+        typename Types::ContentLayerType* surface2 = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(50, 50), IntSize(300, 300), false);
+        surface->setOpaqueContentsRect(IntRect(0, 0, 200, 200));
+        surface2->setOpaqueContentsRect(IntRect(0, 0, 200, 200));
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(surface2, occlusion);
+        this->visitContributingSurface(surface2, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(50, 50, 200, 200), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(50, 50, 200, 200), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // Clear any stored occlusion.
+        occlusion.setOcclusionInScreenSpace(Region());
+        occlusion.setOcclusionInTargetSurface(Region());
+
+        this->visitLayer(surface, occlusion);
+        this->visitContributingSurface(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 400, 400), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 400, 400), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+MAIN_AND_IMPL_THREAD_TEST(CCOcclusionTrackerTestSurfaceOcclusionTranslatesToParent);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceOcclusionTranslatesWithClipping : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 300));
+        parent->setMasksToBounds(true);
+        typename Types::ContentLayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(500, 300), false);
+        surface->setOpaqueContentsRect(IntRect(0, 0, 400, 200));
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(surface, occlusion);
+        this->visitContributingSurface(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 200), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 200), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+MAIN_AND_IMPL_THREAD_TEST(CCOcclusionTrackerTestSurfaceOcclusionTranslatesWithClipping);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestReplicaOccluded : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100), true);
+        this->createReplicaLayer(surface, this->identityMatrix, FloatPoint(0, 100), IntSize(100, 100));
+        typename Types::LayerType* topmost = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(100, 100), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // |topmost| occludes the replica, but not the surface itself.
+        this->visitLayer(topmost, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 100, 100, 100), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 100, 100, 100), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitLayer(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 200), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->enterContributingSurface(surface, occlusion);
+
+        // Surface is not occluded so it shouldn't think it is.
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestReplicaOccluded);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceWithReplicaUnoccluded : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100), true);
+        this->createReplicaLayer(surface, this->identityMatrix, FloatPoint(0, 100), IntSize(100, 100));
+        typename Types::LayerType* topmost = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 110), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // |topmost| occludes the surface, but not the entire surface's replica.
+        this->visitLayer(topmost, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 110), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 110), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitLayer(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 110), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->enterContributingSurface(surface, occlusion);
+
+        // Surface is occluded, but only the top 10px of the replica.
+        EXPECT_RECT_EQ(IntRect(0, 0, 0, 0), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(0, 10, 100, 90), occlusion.unoccludedContributingSurfaceContentRect(surface, true, IntRect(0, 0, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestSurfaceWithReplicaUnoccluded);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceAndReplicaOccludedDifferently : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100), true);
+        this->createReplicaLayer(surface, this->identityMatrix, FloatPoint(0, 100), IntSize(100, 100));
+        typename Types::LayerType* overSurface = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(40, 100), true);
+        typename Types::LayerType* overReplica = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(50, 100), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // These occlude the surface and replica differently, so we can test each one.
+        this->visitLayer(overReplica, occlusion);
+        this->visitLayer(overSurface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 200), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 200), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitLayer(surface, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 200), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->enterContributingSurface(surface, occlusion);
+
+        // Surface and replica are occluded different amounts.
+        EXPECT_RECT_EQ(IntRect(40, 0, 60, 100), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(50, 0, 50, 100), occlusion.unoccludedContributingSurfaceContentRect(surface, true, IntRect(0, 0, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestSurfaceAndReplicaOccludedDifferently);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceChildOfSurface : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        // This test verifies that the surface cliprect does not end up empty and clip away the entire unoccluded rect.
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100), true);
+        typename Types::LayerType* surfaceChild = this->createDrawingSurface(surface, this->identityMatrix, FloatPoint(0, 10), IntSize(100, 50), true);
+        typename Types::LayerType* topmost = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 50), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(-100, -100, 1000, 1000));
+
+        // |topmost| occludes everything partially so we know occlusion is happening at all.
+        this->visitLayer(topmost, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitLayer(surfaceChild, occlusion);
+
+        // surfaceChild increases the occlusion in the screen by a narrow sliver.
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 60), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        // In its own surface, surfaceChild is at 0,0 as is its occlusion.
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // The root layer always has a clipRect. So the parent of |surface| has a clipRect. However, the owning layer for |surface| does not
+        // mask to bounds, so it doesn't have a clipRect of its own. Thus the parent of |surfaceChild| exercises different code paths
+        // as its parent does not have a clipRect.
+
+        this->enterContributingSurface(surfaceChild, occlusion);
+        // The surfaceChild's parent does not have a clipRect as it owns a render surface. Make sure the unoccluded rect
+        // does not get clipped away inappropriately.
+        EXPECT_RECT_EQ(IntRect(0, 40, 100, 10), occlusion.unoccludedContributingSurfaceContentRect(surfaceChild, false, IntRect(0, 0, 100, 50)));
+        this->leaveContributingSurface(surfaceChild, occlusion);
+
+        // When the surfaceChild's occlusion is transformed up to its parent, make sure it is not clipped away inappropriately also.
+        this->enterLayer(surface, occlusion);
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 60), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 10, 100, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+        this->leaveLayer(surface, occlusion);
+
+        this->enterContributingSurface(surface, occlusion);
+        // The surface's parent does have a clipRect as it is the root layer.
+        EXPECT_RECT_EQ(IntRect(0, 50, 100, 50), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestSurfaceChildOfSurface);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestTopmostSurfaceIsClippedToViewport : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        // This test verifies that the top-most surface is considered occluded outside of its target's clipRect and outside the viewport rect.
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(100, 200));
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 300), true);
+        this->calcDrawEtc(parent);
+
+        {
+            // Make a viewport rect that is larger than the root layer.
+            TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+
+            this->visitLayer(surface, occlusion);
+
+            // The root layer always has a clipRect. So the parent of |surface| has a clipRect giving the surface itself a clipRect.
+            this->enterContributingSurface(surface, occlusion);
+            // Make sure the parent's clipRect clips the unoccluded region of the child surface.
+            EXPECT_RECT_EQ(IntRect(0, 0, 100, 200), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 300)));
+        }
+        this->resetLayerIterator();
+        {
+            // Make a viewport rect that is smaller than the root layer.
+            TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 100, 100));
+
+            this->visitLayer(surface, occlusion);
+
+            // The root layer always has a clipRect. So the parent of |surface| has a clipRect giving the surface itself a clipRect.
+            this->enterContributingSurface(surface, occlusion);
+            // Make sure the viewport rect clips the unoccluded region of the child surface.
+            EXPECT_RECT_EQ(IntRect(0, 0, 100, 100), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 300)));
+        }
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestTopmostSurfaceIsClippedToViewport);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestSurfaceChildOfClippingSurface : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        // This test verifies that the surface cliprect does not end up empty and clip away the entire unoccluded rect.
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(80, 200));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* surface = this->createDrawingSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100), true);
+        typename Types::LayerType* surfaceChild = this->createDrawingSurface(surface, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 100), false);
+        typename Types::LayerType* topmost = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(100, 50), true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // |topmost| occludes everything partially so we know occlusion is happening at all.
+        this->visitLayer(topmost, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 80, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 80, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // surfaceChild is not opaque and does not occlude, so we have a non-empty unoccluded area on surface.
+        this->visitLayer(surfaceChild, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 80, 50), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 0, 0), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // The root layer always has a clipRect. So the parent of |surface| has a clipRect. However, the owning layer for |surface| does not
+        // mask to bounds, so it doesn't have a clipRect of its own. Thus the parent of |surfaceChild| exercises different code paths
+        // as its parent does not have a clipRect.
+
+        this->enterContributingSurface(surfaceChild, occlusion);
+        // The surfaceChild's parent does not have a clipRect as it owns a render surface.
+        EXPECT_RECT_EQ(IntRect(0, 50, 80, 50), occlusion.unoccludedContributingSurfaceContentRect(surfaceChild, false, IntRect(0, 0, 100, 100)));
+        this->leaveContributingSurface(surfaceChild, occlusion);
+
+        this->visitLayer(surface, occlusion);
+        this->enterContributingSurface(surface, occlusion);
+        // The surface's parent does have a clipRect as it is the root layer.
+        EXPECT_RECT_EQ(IntRect(0, 50, 80, 50), occlusion.unoccludedContributingSurfaceContentRect(surface, false, IntRect(0, 0, 100, 100)));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestSurfaceChildOfClippingSurface);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestDontOccludePixelsNeededForBackgroundFilter : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix scaleByHalf;
+        scaleByHalf.scale(0.5);
+
+        // Make a surface and its replica, each 50x50, that are completely surrounded by opaque layers which are above them in the z-order.
+        // The surface is scaled to test that the pixel moving is done in the target space, where the background filter is applied, but the surface
+        // appears at 50, 50 and the replica at 200, 50.
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 150));
+        typename Types::LayerType* filteredSurface = this->createDrawingLayer(parent, scaleByHalf, FloatPoint(50, 50), IntSize(100, 100), false);
+        this->createReplicaLayer(filteredSurface, this->identityMatrix, FloatPoint(300, 0), IntSize());
+        typename Types::LayerType* occludingLayer1 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 50), true);
+        typename Types::LayerType* occludingLayer2 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(300, 50), true);
+        typename Types::LayerType* occludingLayer3 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 50), IntSize(50, 50), true);
+        typename Types::LayerType* occludingLayer4 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(100, 50), IntSize(100, 50), true);
+        typename Types::LayerType* occludingLayer5 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(250, 50), IntSize(50, 50), true);
+
+        // Filters make the layer own a surface.
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(10));
+        filteredSurface->setBackgroundFilters(filters);
+
+        // Save the distance of influence for the blur effect.
+        int outsetTop, outsetRight, outsetBottom, outsetLeft;
+        filters.getOutsets(outsetTop, outsetRight, outsetBottom, outsetLeft);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // These layers occlude pixels directly beside the filteredSurface. Because filtered surface blends pixels in a radius, it will
+        // need to see some of the pixels (up to radius far) underneath the occludingLayers.
+        this->visitLayer(occludingLayer5, occlusion);
+        this->visitLayer(occludingLayer4, occlusion);
+        this->visitLayer(occludingLayer3, occlusion);
+        this->visitLayer(occludingLayer2, occlusion);
+        this->visitLayer(occludingLayer1, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // Everything outside the surface/replica is occluded but the surface/replica itself is not.
+        this->enterLayer(filteredSurface, occlusion);
+        EXPECT_RECT_EQ(IntRect(1, 0, 99, 100), occlusion.unoccludedContentRect(filteredSurface, IntRect(1, 0, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(0, 1, 100, 99), occlusion.unoccludedContentRect(filteredSurface, IntRect(0, 1, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(0, 0, 99, 100), occlusion.unoccludedContentRect(filteredSurface, IntRect(-1, 0, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(0, 0, 100, 99), occlusion.unoccludedContentRect(filteredSurface, IntRect(0, -1, 100, 100)));
+
+        EXPECT_RECT_EQ(IntRect(300 + 1, 0, 99, 100), occlusion.unoccludedContentRect(filteredSurface, IntRect(300 + 1, 0, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(300 + 0, 1, 100, 99), occlusion.unoccludedContentRect(filteredSurface, IntRect(300 + 0, 1, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(300 + 0, 0, 99, 100), occlusion.unoccludedContentRect(filteredSurface, IntRect(300 - 1, 0, 100, 100)));
+        EXPECT_RECT_EQ(IntRect(300 + 0, 0, 100, 99), occlusion.unoccludedContentRect(filteredSurface, IntRect(300 + 0, -1, 100, 100)));
+        this->leaveLayer(filteredSurface, occlusion);
+
+        // The filtered layer/replica does not occlude.
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 0, 0), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // The surface has a background blur, so it needs pixels that are currently considered occluded in order to be drawn. So the pixels
+        // it needs should be removed some the occluded area so that when we get to the parent they are drawn.
+        this->visitContributingSurface(filteredSurface, occlusion);
+
+        this->enterLayer(parent, occlusion);
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInTargetSurface().rects().size());
+
+        IntRect outsetRect;
+        IntRect testRect;
+
+        // Nothing in the blur outsets for the filteredSurface is occluded.
+        outsetRect = IntRect(50 - outsetLeft, 50 - outsetTop, 50 + outsetLeft + outsetRight, 50 + outsetTop + outsetBottom);
+        testRect = outsetRect;
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+
+        // Stuff outside the blur outsets is still occluded though.
+        testRect = outsetRect;
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+        testRect = outsetRect;
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+        testRect = outsetRect;
+        testRect.move(-1, 0);
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+        testRect = outsetRect;
+        testRect.move(0, -1);
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+
+        // Nothing in the blur outsets for the filteredSurface's replica is occluded.
+        outsetRect = IntRect(200 - outsetLeft, 50 - outsetTop, 50 + outsetLeft + outsetRight, 50 + outsetTop + outsetBottom);
+        testRect = outsetRect;
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+
+        // Stuff outside the blur outsets is still occluded though.
+        testRect = outsetRect;
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+        testRect = outsetRect;
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+        testRect = outsetRect;
+        testRect.move(-1, 0);
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+        testRect = outsetRect;
+        testRect.move(0, -1);
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(outsetRect, occlusion.unoccludedContentRect(parent, testRect));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestDontOccludePixelsNeededForBackgroundFilter);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestTwoBackgroundFiltersReduceOcclusionTwice : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix scaleByHalf;
+        scaleByHalf.scale(0.5);
+
+        // Makes two surfaces that completely cover |parent|. The occlusion both above and below the filters will be reduced by each of them.
+        typename Types::ContentLayerType* root = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(75, 75));
+        typename Types::LayerType* parent = this->createSurface(root, scaleByHalf, FloatPoint(0, 0), IntSize(150, 150));
+        parent->setMasksToBounds(true);
+        typename Types::LayerType* filteredSurface1 = this->createDrawingLayer(parent, scaleByHalf, FloatPoint(0, 0), IntSize(300, 300), false);
+        typename Types::LayerType* filteredSurface2 = this->createDrawingLayer(parent, scaleByHalf, FloatPoint(0, 0), IntSize(300, 300), false);
+        typename Types::LayerType* occludingLayerAbove = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(100, 100), IntSize(50, 50), true);
+
+        // Filters make the layers own surfaces.
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(3));
+        filteredSurface1->setBackgroundFilters(filters);
+        filteredSurface2->setBackgroundFilters(filters);
+
+        // Save the distance of influence for the blur effect.
+        int outsetTop, outsetRight, outsetBottom, outsetLeft;
+        filters.getOutsets(outsetTop, outsetRight, outsetBottom, outsetLeft);
+
+        this->calcDrawEtc(root);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(occludingLayerAbove, occlusion);
+        EXPECT_RECT_EQ(IntRect(100 / 2, 100 / 2, 50 / 2, 50 / 2), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(100, 100, 50, 50), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        this->visitLayer(filteredSurface2, occlusion);
+        this->visitContributingSurface(filteredSurface2, occlusion);
+        this->visitLayer(filteredSurface1, occlusion);
+        this->visitContributingSurface(filteredSurface1, occlusion);
+
+        ASSERT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        ASSERT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // Test expectations in the target.
+        IntRect expectedOcclusion = IntRect(100 + outsetRight * 2, 100 + outsetBottom * 2, 50 - (outsetLeft + outsetRight) * 2, 50 - (outsetTop + outsetBottom) * 2);
+        EXPECT_RECT_EQ(expectedOcclusion, occlusion.occlusionInTargetSurface().rects()[0]);
+
+        // Test expectations in the screen. Take the ceiling of half of the outsets.
+        outsetTop = (outsetTop + 1) / 2;
+        outsetRight = (outsetRight + 1) / 2;
+        outsetBottom = (outsetBottom + 1) / 2;
+        outsetLeft = (outsetLeft + 1) / 2;
+        expectedOcclusion = IntRect(100 / 2 + outsetRight * 2, 100 / 2 + outsetBottom * 2, 50 / 2 - (outsetLeft + outsetRight) * 2, 50 /2 - (outsetTop + outsetBottom) * 2);
+
+        EXPECT_RECT_EQ(expectedOcclusion, occlusion.occlusionInScreenSpace().rects()[0]);
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestTwoBackgroundFiltersReduceOcclusionTwice);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestDontOccludePixelsNeededForBackgroundFilterWithClip : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        // Make a surface and its replica, each 50x50, that are completely surrounded by opaque layers which are above them in the z-order.
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 150));
+        // We stick the filtered surface inside a clipping surface so that we can make sure the clip is honored when exposing pixels for
+        // the background filter.
+        typename Types::LayerType* clippingSurface = this->createSurface(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 70));
+        clippingSurface->setMasksToBounds(true);
+        typename Types::LayerType* filteredSurface = this->createDrawingLayer(clippingSurface, this->identityMatrix, FloatPoint(50, 50), IntSize(50, 50), false);
+        this->createReplicaLayer(filteredSurface, this->identityMatrix, FloatPoint(150, 0), IntSize());
+        typename Types::LayerType* occludingLayer1 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), IntSize(300, 50), true);
+        typename Types::LayerType* occludingLayer2 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 100), IntSize(300, 50), true);
+        typename Types::LayerType* occludingLayer3 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 50), IntSize(50, 50), true);
+        typename Types::LayerType* occludingLayer4 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(100, 50), IntSize(100, 50), true);
+        typename Types::LayerType* occludingLayer5 = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(250, 50), IntSize(50, 50), true);
+
+        // Filters make the layer own a surface. This filter is large enough that it goes outside the bottom of the clippingSurface.
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(12));
+        filteredSurface->setBackgroundFilters(filters);
+
+        // Save the distance of influence for the blur effect.
+        int outsetTop, outsetRight, outsetBottom, outsetLeft;
+        filters.getOutsets(outsetTop, outsetRight, outsetBottom, outsetLeft);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // These layers occlude pixels directly beside the filteredSurface. Because filtered surface blends pixels in a radius, it will
+        // need to see some of the pixels (up to radius far) underneath the occludingLayers.
+        this->visitLayer(occludingLayer5, occlusion);
+        this->visitLayer(occludingLayer4, occlusion);
+        this->visitLayer(occludingLayer3, occlusion);
+        this->visitLayer(occludingLayer2, occlusion);
+        this->visitLayer(occludingLayer1, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // Everything outside the surface/replica is occluded but the surface/replica itself is not.
+        this->enterLayer(filteredSurface, occlusion);
+        EXPECT_RECT_EQ(IntRect(1, 0, 49, 50), occlusion.unoccludedContentRect(filteredSurface, IntRect(1, 0, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(0, 1, 50, 49), occlusion.unoccludedContentRect(filteredSurface, IntRect(0, 1, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(0, 0, 49, 50), occlusion.unoccludedContentRect(filteredSurface, IntRect(-1, 0, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(0, 0, 50, 49), occlusion.unoccludedContentRect(filteredSurface, IntRect(0, -1, 50, 50)));
+
+        EXPECT_RECT_EQ(IntRect(150 + 1, 0, 49, 50), occlusion.unoccludedContentRect(filteredSurface, IntRect(150 + 1, 0, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(150 + 0, 1, 50, 49), occlusion.unoccludedContentRect(filteredSurface, IntRect(150 + 0, 1, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(150 + 0, 0, 49, 50), occlusion.unoccludedContentRect(filteredSurface, IntRect(150 - 1, 0, 50, 50)));
+        EXPECT_RECT_EQ(IntRect(150 + 0, 0, 50, 49), occlusion.unoccludedContentRect(filteredSurface, IntRect(150 + 0, -1, 50, 50)));
+        this->leaveLayer(filteredSurface, occlusion);
+
+        // The filtered layer/replica does not occlude.
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(0, 0, 0, 0), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // The surface has a background blur, so it needs pixels that are currently considered occluded in order to be drawn. So the pixels
+        // it needs should be removed some the occluded area so that when we get to the parent they are drawn.
+        this->visitContributingSurface(filteredSurface, occlusion);
+
+        this->enterContributingSurface(clippingSurface, occlusion);
+        EXPECT_RECT_EQ(IntRect(0, 0, 300, 150), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(5u, occlusion.occlusionInScreenSpace().rects().size());
+
+        IntRect outsetRect;
+        IntRect clippedOutsetRect;
+        IntRect testRect;
+
+        // Nothing in the (clipped) blur outsets for the filteredSurface is occluded.
+        outsetRect = IntRect(50 - outsetLeft, 50 - outsetTop, 50 + outsetLeft + outsetRight, 50 + outsetTop + outsetBottom);
+        clippedOutsetRect = intersection(outsetRect, IntRect(0 - outsetLeft, 0 - outsetTop, 300 + outsetLeft + outsetRight, 70 + outsetTop + outsetBottom));
+        testRect = outsetRect;
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+
+        // Stuff outside the (clipped) blur outsets is still occluded though.
+        testRect = outsetRect;
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+        testRect = outsetRect;
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+        testRect = outsetRect;
+        testRect.move(-1, 0);
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+        testRect = outsetRect;
+        testRect.move(0, -1);
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+
+        // Nothing in the (clipped) blur outsets for the filteredSurface's replica is occluded.
+        outsetRect = IntRect(200 - outsetLeft, 50 - outsetTop, 50 + outsetLeft + outsetRight, 50 + outsetTop + outsetBottom);
+        clippedOutsetRect = intersection(outsetRect, IntRect(0 - outsetLeft, 0 - outsetTop, 300 + outsetLeft + outsetRight, 70 + outsetTop + outsetBottom));
+        testRect = outsetRect;
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+
+        // Stuff outside the (clipped) blur outsets is still occluded though.
+        testRect = outsetRect;
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+        testRect = outsetRect;
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+        testRect = outsetRect;
+        testRect.move(-1, 0);
+        testRect.expand(1, 0);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+        testRect = outsetRect;
+        testRect.move(0, -1);
+        testRect.expand(0, 1);
+        EXPECT_RECT_EQ(clippedOutsetRect, occlusion.unoccludedContentRect(clippingSurface, testRect));
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestDontOccludePixelsNeededForBackgroundFilterWithClip);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestDontReduceOcclusionBelowBackgroundFilter : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix scaleByHalf;
+        scaleByHalf.scale(0.5);
+
+        // Make a surface and its replica, each 50x50, with a smaller 30x30 layer centered below each.
+        // The surface is scaled to test that the pixel moving is done in the target space, where the background filter is applied, but the surface
+        // appears at 50, 50 and the replica at 200, 50.
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 150));
+        typename Types::LayerType* behindSurfaceLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(60, 60), IntSize(30, 30), true);
+        typename Types::LayerType* behindReplicaLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(210, 60), IntSize(30, 30), true);
+        typename Types::LayerType* filteredSurface = this->createDrawingLayer(parent, scaleByHalf, FloatPoint(50, 50), IntSize(100, 100), false);
+        this->createReplicaLayer(filteredSurface, this->identityMatrix, FloatPoint(300, 0), IntSize());
+
+        // Filters make the layer own a surface.
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(3));
+        filteredSurface->setBackgroundFilters(filters);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        // The surface has a background blur, so it blurs non-opaque pixels below it.
+        this->visitLayer(filteredSurface, occlusion);
+        this->visitContributingSurface(filteredSurface, occlusion);
+
+        this->visitLayer(behindReplicaLayer, occlusion);
+        this->visitLayer(behindSurfaceLayer, occlusion);
+
+        // The layers behind the surface are not blurred, and their occlusion does not change, until we leave the surface.
+        // So it should not be modified by the filter here.
+        IntRect occlusionBehindSurface = IntRect(60, 60, 30, 30);
+        IntRect occlusionBehindReplica = IntRect(210, 60, 30, 30);
+
+        IntRect expectedOpaqueBounds = unionRect(occlusionBehindSurface, occlusionBehindReplica);
+        EXPECT_RECT_EQ(expectedOpaqueBounds, occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(expectedOpaqueBounds, occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestDontReduceOcclusionBelowBackgroundFilter);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestDontReduceOcclusionIfBackgroundFilterIsOccluded : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix scaleByHalf;
+        scaleByHalf.scale(0.5);
+
+        // Make a surface and its replica, each 50x50, that are completely occluded by opaque layers which are above them in the z-order.
+        // The surface is scaled to test that the pixel moving is done in the target space, where the background filter is applied, but the surface
+        // appears at 50, 50 and the replica at 200, 50.
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 150));
+        typename Types::LayerType* filteredSurface = this->createDrawingLayer(parent, scaleByHalf, FloatPoint(50, 50), IntSize(100, 100), false);
+        this->createReplicaLayer(filteredSurface, this->identityMatrix, FloatPoint(300, 0), IntSize());
+        typename Types::LayerType* aboveSurfaceLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(50, 50), IntSize(50, 50), true);
+        typename Types::LayerType* aboveReplicaLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(200, 50), IntSize(50, 50), true);
+
+        // Filters make the layer own a surface.
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(3));
+        filteredSurface->setBackgroundFilters(filters);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(aboveReplicaLayer, occlusion);
+        this->visitLayer(aboveSurfaceLayer, occlusion);
+
+        // The surface has a background blur, so it blurs non-opaque pixels below it.
+        this->visitLayer(filteredSurface, occlusion);
+        this->visitContributingSurface(filteredSurface, occlusion);
+
+        // The filter is completely occluded, so it should not blur anything and reduce any occlusion.
+        IntRect occlusionAboveSurface = IntRect(50, 50, 50, 50);
+        IntRect occlusionAboveReplica = IntRect(200, 50, 50, 50);
+
+        IntRect expectedOpaqueBounds = unionRect(occlusionAboveSurface, occlusionAboveReplica);
+        EXPECT_RECT_EQ(expectedOpaqueBounds, occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(expectedOpaqueBounds, occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(2u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestDontReduceOcclusionIfBackgroundFilterIsOccluded);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestReduceOcclusionWhenBackgroundFilterIsPartiallyOccluded : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        WebTransformationMatrix scaleByHalf;
+        scaleByHalf.scale(0.5);
+
+        // Make a surface and its replica, each 50x50, that are partially occluded by opaque layers which are above them in the z-order.
+        // The surface is scaled to test that the pixel moving is done in the target space, where the background filter is applied, but the surface
+        // appears at 50, 50 and the replica at 200, 50.
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(300, 150));
+        typename Types::LayerType* filteredSurface = this->createDrawingLayer(parent, scaleByHalf, FloatPoint(50, 50), IntSize(100, 100), false);
+        this->createReplicaLayer(filteredSurface, this->identityMatrix, FloatPoint(300, 0), IntSize());
+        typename Types::LayerType* aboveSurfaceLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(70, 50), IntSize(30, 50), true);
+        typename Types::LayerType* aboveReplicaLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(200, 50), IntSize(30, 50), true);
+        typename Types::LayerType* besideSurfaceLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(90, 40), IntSize(10, 10), true);
+        typename Types::LayerType* besideReplicaLayer = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(200, 40), IntSize(10, 10), true);
+
+        // Filters make the layer own a surface.
+        WebFilterOperations filters;
+        filters.append(WebFilterOperation::createBlurFilter(3));
+        filteredSurface->setBackgroundFilters(filters);
+
+        // Save the distance of influence for the blur effect.
+        int outsetTop, outsetRight, outsetBottom, outsetLeft;
+        filters.getOutsets(outsetTop, outsetRight, outsetBottom, outsetLeft);
+
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+
+        this->visitLayer(besideReplicaLayer, occlusion);
+        this->visitLayer(besideSurfaceLayer, occlusion);
+        this->visitLayer(aboveReplicaLayer, occlusion);
+        this->visitLayer(aboveSurfaceLayer, occlusion);
+
+        // The surface has a background blur, so it blurs non-opaque pixels below it.
+        this->visitLayer(filteredSurface, occlusion);
+        this->visitContributingSurface(filteredSurface, occlusion);
+
+        // The filter in the surface and replica are partially unoccluded. Only the unoccluded parts should reduce occlusion.
+        // This means it will push back the occlusion that touches the unoccluded part (occlusionAbove___), but it will not
+        // touch occlusionBeside____ since that is not beside the unoccluded part of the surface, even though it is beside
+        // the occluded part of the surface.
+        IntRect occlusionAboveSurface = IntRect(70 + outsetRight, 50, 30 - outsetRight, 50);
+        IntRect occlusionAboveReplica = IntRect(200, 50, 30 - outsetLeft, 50);
+        IntRect occlusionBesideSurface = IntRect(90, 40, 10, 10);
+        IntRect occlusionBesideReplica = IntRect(200, 40, 10, 10);
+
+        Region expectedOcclusion;
+        expectedOcclusion.unite(occlusionAboveSurface);
+        expectedOcclusion.unite(occlusionAboveReplica);
+        expectedOcclusion.unite(occlusionBesideSurface);
+        expectedOcclusion.unite(occlusionBesideReplica);
+
+        ASSERT_EQ(expectedOcclusion.rects().size(), occlusion.occlusionInTargetSurface().rects().size());
+        ASSERT_EQ(expectedOcclusion.rects().size(), occlusion.occlusionInScreenSpace().rects().size());
+
+        for (size_t i = 0; i < expectedOcclusion.rects().size(); ++i) {
+            IntRect expectedRect = expectedOcclusion.rects()[i];
+            IntRect screenRect = occlusion.occlusionInScreenSpace().rects()[i];
+            IntRect targetRect = occlusion.occlusionInTargetSurface().rects()[i];
+            EXPECT_EQ(expectedRect, screenRect);
+            EXPECT_EQ(expectedRect, targetRect);
+        }
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestReduceOcclusionWhenBackgroundFilterIsPartiallyOccluded);
+
+template<class Types, bool opaqueLayers>
+class CCOcclusionTrackerTestMinimumTrackingSize : public CCOcclusionTrackerTest<Types, opaqueLayers> {
+protected:
+    void runMyTest()
+    {
+        IntSize trackingSize(100, 100);
+        IntSize belowTrackingSize(99, 99);
+
+        typename Types::ContentLayerType* parent = this->createRoot(this->identityMatrix, FloatPoint(0, 0), IntSize(400, 400));
+        typename Types::LayerType* large = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), trackingSize, true);
+        typename Types::LayerType* small = this->createDrawingLayer(parent, this->identityMatrix, FloatPoint(0, 0), belowTrackingSize, true);
+        this->calcDrawEtc(parent);
+
+        TestCCOcclusionTrackerWithClip<typename Types::LayerType, typename Types::RenderSurfaceType> occlusion(IntRect(0, 0, 1000, 1000));
+        occlusion.setLayerClipRect(IntRect(0, 0, 1000, 1000));
+        occlusion.setMinimumTrackingSize(trackingSize);
+
+        // The small layer is not tracked because it is too small.
+        this->visitLayer(small, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(0u, occlusion.occlusionInTargetSurface().rects().size());
+
+        // The large layer is tracked as it is large enough.
+        this->visitLayer(large, occlusion);
+
+        EXPECT_RECT_EQ(IntRect(IntPoint(), trackingSize), occlusion.occlusionInScreenSpace().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInScreenSpace().rects().size());
+        EXPECT_RECT_EQ(IntRect(IntPoint(), trackingSize), occlusion.occlusionInTargetSurface().bounds());
+        EXPECT_EQ(1u, occlusion.occlusionInTargetSurface().rects().size());
+    }
+};
+
+ALL_CCOCCLUSIONTRACKER_TEST(CCOcclusionTrackerTestMinimumTrackingSize);
+
+} // namespace