Chromium compositor change implementing page-scale driven pinch-zoom.

cc/CCLayerTreeHostImplTest.cpp

Index: cc/CCLayerTreeHostImplTest.cpp
===================================================================
--- cc/CCLayerTreeHostImplTest.cpp	(revision 158365)
+++ cc/CCLayerTreeHostImplTest.cpp	(working copy)
@@ -452,6 +452,60 @@
     EXPECT_EQ(m_hostImpl->rootLayer()->maxScrollPosition(), IntSize(75, 75));
 }
 
+TEST_F(CCLayerTreeHostImplTest, implPinchZoom)
+{
+    CCSettings::setPageScalePinchZoomEnabled(true);
+    setupScrollAndContentsLayers(IntSize(100, 100));
+    m_hostImpl->setViewportSize(IntSize(50, 50), IntSize(50, 50));
+    initializeRendererAndDrawFrame();
+
+    CCLayerImpl* scrollLayer = m_hostImpl->rootScrollLayer();
+    ASSERT(scrollLayer);
+
+    const float minPageScale = 1, maxPageScale = 4;
+    const WebTransformationMatrix identityScaleTransform;
+
+    // The impl-based pinch zoome should not adjust the max scroll position.
+    {
+        m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
+        scrollLayer->setImplTransform(identityScaleTransform);
+        scrollLayer->setScrollDelta(IntSize());
+
+        float pageScaleDelta = 2;
+        m_hostImpl->pinchGestureBegin();
+        m_hostImpl->pinchGestureUpdate(pageScaleDelta, IntPoint(50, 50));
+        m_hostImpl->pinchGestureEnd();
+        EXPECT_TRUE(m_didRequestRedraw);
+        EXPECT_TRUE(m_didRequestCommit);
+
+        OwnPtr<CCScrollAndScaleSet> scrollInfo = m_hostImpl->processScrollDeltas();
+        EXPECT_EQ(scrollInfo->pageScaleDelta, pageScaleDelta);
+
+        EXPECT_EQ(m_hostImpl->rootLayer()->maxScrollPosition(), IntSize(50, 50));
+    }
+
+    // Scrolling after a pinch gesture should always be in local space.  The scroll deltas do not
+    // have the page scale factor applied.
+    {
+        m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
+        scrollLayer->setImplTransform(identityScaleTransform);
+        scrollLayer->setScrollDelta(IntSize());
+
+        float pageScaleDelta = 2;
+        m_hostImpl->pinchGestureBegin();
+        m_hostImpl->pinchGestureUpdate(pageScaleDelta, IntPoint(50, 50));
+        m_hostImpl->pinchGestureEnd();
+
+        IntSize scrollDelta(0, 10);
+        EXPECT_EQ(m_hostImpl->scrollBegin(IntPoint(5, 5), CCInputHandlerClient::Wheel), CCInputHandlerClient::ScrollStarted);
+        m_hostImpl->scrollBy(IntPoint(), scrollDelta);
+        m_hostImpl->scrollEnd();
+
+        OwnPtr<CCScrollAndScaleSet> scrollInfo = m_hostImpl->processScrollDeltas();
+        expectContains(*scrollInfo.get(), m_hostImpl->rootLayer()->id(), scrollDelta);
+    }
+}
+
 TEST_F(CCLayerTreeHostImplTest, pinchGesture)
 {
     setupScrollAndContentsLayers(IntSize(100, 100));
@@ -462,11 +516,12 @@
     ASSERT(scrollLayer);
 
     const float minPageScale = 0.5, maxPageScale = 4;
+    const WebTransformationMatrix identityScaleTransform;
 
     // Basic pinch zoom in gesture
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
-        scrollLayer->setPageScaleDelta(1);
+        scrollLayer->setImplTransform(identityScaleTransform);
         scrollLayer->setScrollDelta(IntSize());
 
         float pageScaleDelta = 2;
@@ -483,7 +538,7 @@
     // Zoom-in clamping
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
-        scrollLayer->setPageScaleDelta(1);
+        scrollLayer->setImplTransform(identityScaleTransform);
         scrollLayer->setScrollDelta(IntSize());
         float pageScaleDelta = 10;
 
@@ -498,7 +553,7 @@
     // Zoom-out clamping
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
-        scrollLayer->setPageScaleDelta(1);
+        scrollLayer->setImplTransform(identityScaleTransform);
         scrollLayer->setScrollDelta(IntSize());
         scrollLayer->setScrollPosition(IntPoint(50, 50));
 
@@ -517,7 +572,7 @@
     // Two-finger panning
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
-        scrollLayer->setPageScaleDelta(1);
+        scrollLayer->setImplTransform(identityScaleTransform);
         scrollLayer->setScrollDelta(IntSize());
         scrollLayer->setScrollPosition(IntPoint(20, 20));
 
@@ -547,11 +602,12 @@
     const double duration = 0.1;
     const double halfwayThroughAnimation = startTime + duration / 2;
     const double endTime = startTime + duration;
+    const WebTransformationMatrix identityScaleTransform;
 
     // Non-anchor zoom-in
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
-        scrollLayer->setPageScaleDelta(1);
+        scrollLayer->setImplTransform(identityScaleTransform);
         scrollLayer->setScrollPosition(IntPoint(50, 50));
 
         m_hostImpl->startPageScaleAnimation(IntSize(0, 0), false, 2, startTime, duration);
@@ -568,7 +624,7 @@
     // Anchor zoom-out
     {
         m_hostImpl->setPageScaleFactorAndLimits(1, minPageScale, maxPageScale);
-        scrollLayer->setPageScaleDelta(1);
+        scrollLayer->setImplTransform(identityScaleTransform);
         scrollLayer->setScrollPosition(IntPoint(50, 50));
 
         m_hostImpl->startPageScaleAnimation(IntSize(25, 25), true, minPageScale, startTime, duration);
@@ -1046,7 +1102,7 @@
     EXPECT_EQ(m_hostImpl->rootLayer()->maxScrollPosition(), expectedMaxScroll);
 
     // The page scale delta remains constant because the impl thread did not scale.
-    EXPECT_EQ(m_hostImpl->rootLayer()->pageScaleDelta(), 1);
+    EXPECT_EQ(m_hostImpl->rootLayer()->implTransform(), WebTransformationMatrix());
 }
 
 TEST_F(CCLayerTreeHostImplTest, scrollRootAndChangePageScaleOnImplThread)
@@ -1070,6 +1126,7 @@
     m_hostImpl->pinchGestureBegin();
     m_hostImpl->pinchGestureUpdate(pageScale, IntPoint());
     m_hostImpl->pinchGestureEnd();
+    m_hostImpl->updateRootScrollLayerImplTransform();
 
     // The scroll delta is not scaled because the main thread did not scale.
     OwnPtr<CCScrollAndScaleSet> scrollInfo = m_hostImpl->processScrollDeltas();
@@ -1079,14 +1136,20 @@
     EXPECT_EQ(m_hostImpl->rootLayer()->maxScrollPosition(), expectedMaxScroll);
 
     // The page scale delta should match the new scale on the impl side.
-    EXPECT_EQ(m_hostImpl->rootLayer()->pageScaleDelta(), pageScale);
+    WebTransformationMatrix expectedScale;
+    expectedScale.scale(pageScale);
+    EXPECT_EQ(m_hostImpl->rootLayer()->implTransform(), expectedScale);
 }
 
 TEST_F(CCLayerTreeHostImplTest, pageScaleDeltaAppliedToRootScrollLayerOnly)
 {
     IntSize surfaceSize(10, 10);
     float defaultPageScale = 1;
+    WebTransformationMatrix defaultPageScaleMatrix;
+
     float newPageScale = 2;
+    WebTransformationMatrix newPageScaleMatrix;
+    newPageScaleMatrix.scale(newPageScale);
 
     // Create a normal scrollable root layer and another scrollable child layer.
     setupScrollAndContentsLayers(surfaceSize);
@@ -1101,11 +1164,12 @@
     m_hostImpl->pinchGestureBegin();
     m_hostImpl->pinchGestureUpdate(newPageScale, IntPoint());
     m_hostImpl->pinchGestureEnd();
+    m_hostImpl->updateRootScrollLayerImplTransform();
 
     // The page scale delta should only be applied to the scrollable root layer.
-    EXPECT_EQ(root->pageScaleDelta(), newPageScale);
-    EXPECT_EQ(child->pageScaleDelta(), defaultPageScale);
-    EXPECT_EQ(grandChild->pageScaleDelta(), defaultPageScale);
+    EXPECT_EQ(root->implTransform(), newPageScaleMatrix);
+    EXPECT_EQ(child->implTransform(), defaultPageScaleMatrix);
+    EXPECT_EQ(grandChild->implTransform(), defaultPageScaleMatrix);
 
     // Make sure all the layers are drawn with the page scale delta applied, i.e., the page scale
     // delta on the root layer is applied hierarchically.
@@ -1148,6 +1212,8 @@
     float pageScale = 2;
     m_hostImpl->setPageScaleFactorAndLimits(pageScale, 1, pageScale);
 
+    m_hostImpl->updateRootScrollLayerImplTransform();
+
     // The scale should apply to the scroll delta.
     expectedScrollDelta.scale(pageScale);
     OwnPtr<CCScrollAndScaleSet> scrollInfo = m_hostImpl->processScrollDeltas();
@@ -1157,7 +1223,8 @@
     EXPECT_EQ(child->maxScrollPosition(), expectedMaxScroll);
 
     // The page scale delta remains constant because the impl thread did not scale.
-    EXPECT_EQ(child->pageScaleDelta(), 1);
+    WebTransformationMatrix identityTransform;
+    EXPECT_EQ(child->implTransform(), WebTransformationMatrix());
 }
 
 TEST_F(CCLayerTreeHostImplTest, scrollChildBeyondLimit)