Support for mapping from outer/visual to flowthread coord space in nested multicol.

third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp

Index: third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp b/third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp
index 086bd8d982d2605353ad69deaed12cb65d086a4e..06c5ae0c035142a85c3b9239d80aba32e6728f66 100644
--- a/third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp
+++ b/third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp
@@ -575,21 +575,29 @@ TEST_F(MapCoordinatesTest, NestedMulticolWithBlock)
 
     FloatPoint mappedPoint = mapLocalToAncestor(target, outerMulticol, FloatPoint());
     EXPECT_EQ(FloatPoint(435, 115), mappedPoint);
-
-    // TODO(mstensho): Add mapAncestorToLocal() tests when it starts working in nested multicol.
+    mappedPoint = mapAncestorToLocal(target, outerMulticol, mappedPoint);
+    EXPECT_EQ(FloatPoint(), mappedPoint);
 
     // Walk each ancestor in the chain separately, to verify each step on the way.
     mappedPoint = mapLocalToAncestor(target, innerFlowThread, FloatPoint());
     EXPECT_EQ(FloatPoint(0, 630), mappedPoint);
+    mappedPoint = mapAncestorToLocal(target, innerFlowThread, mappedPoint);
+    EXPECT_EQ(FloatPoint(), mappedPoint);
 
-    mappedPoint = mapLocalToAncestor(innerFlowThread, innerMulticol, mappedPoint);
+    mappedPoint = mapLocalToAncestor(innerFlowThread, innerMulticol, FloatPoint(0, 630));
     EXPECT_EQ(FloatPoint(140, 305), mappedPoint);
+    mappedPoint = mapAncestorToLocal(innerFlowThread, innerMulticol, mappedPoint);
+    EXPECT_EQ(FloatPoint(0, 630), mappedPoint);
 
-    mappedPoint = mapLocalToAncestor(innerMulticol, outerFlowThread, mappedPoint);
+    mappedPoint = mapLocalToAncestor(innerMulticol, outerFlowThread, FloatPoint(140, 305));
     EXPECT_EQ(FloatPoint(140, 315), mappedPoint);
+    mappedPoint = mapAncestorToLocal(innerMulticol, outerFlowThread, mappedPoint);
+    EXPECT_EQ(FloatPoint(140, 305), mappedPoint);
 
-    mappedPoint = mapLocalToAncestor(outerFlowThread, outerMulticol, mappedPoint);
+    mappedPoint = mapLocalToAncestor(outerFlowThread, outerMulticol, FloatPoint(140, 315));
     EXPECT_EQ(FloatPoint(435, 115), mappedPoint);
+    mappedPoint = mapAncestorToLocal(outerFlowThread, outerMulticol, mappedPoint);
+    EXPECT_EQ(FloatPoint(140, 315), mappedPoint);
 }
 
 TEST_F(MapCoordinatesTest, MulticolWithAbsPosInRelPos)