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

third_party/WebKit/LayoutTests/fast/multicol/event-offset-in-nested.html

Index: third_party/WebKit/LayoutTests/fast/multicol/event-offset-in-nested.html
diff --git a/third_party/WebKit/LayoutTests/fast/multicol/event-offset-complex-tree.html b/third_party/WebKit/LayoutTests/fast/multicol/event-offset-in-nested.html
similarity index 54%
copy from third_party/WebKit/LayoutTests/fast/multicol/event-offset-complex-tree.html
copy to third_party/WebKit/LayoutTests/fast/multicol/event-offset-in-nested.html
index d0ab17ef705e4c35fa06c49baa75b45d16d7ff27..7d62df7c7792ce47ac3d608545d9df9d7a4a97cb 100644
--- a/third_party/WebKit/LayoutTests/fast/multicol/event-offset-complex-tree.html
+++ b/third_party/WebKit/LayoutTests/fast/multicol/event-offset-in-nested.html
@@ -4,34 +4,52 @@ body {
     margin: 0;
 }
 
-#columns {
+#outerColumns {
     position: absolute;
     width: 332px;
     height: 200px;
-    top: 320px;
+    top: 220px;
     left: 300px;
     border: 1px solid black;
-    -webkit-column-count: 3;
-    -webkit-column-gap: 16px;
+    columns: 3;
+    column-gap: 16px;
     column-fill: auto;
     line-height: 50px;
+    orphans: 1;
+    widows: 1;
+}
+
+#innerColumns {
+    columns: 2;
+    column-gap: 0;
 }
 </style>
 
-<div id="columns">
-    <br>
+<div id="outerColumns">
     <br>
-    <div>
+    <div id="innerColumns">
+        <br>
+        <br>
+        <div id="outer1-inner1">first</div>
+        <br>
+        <div id="outer1-inner2">second</div>
+        <br>
+        <br>
+        <div id="outer2-inner1">third</div>
+        <br>
+        <br>
+        <div id="outer2-inner2">fourth</div>
+        <br>
+        <br>
+        <br>
+        <br>
+        <br>
+        <div id="outer3-inner1">fifth</div>
         <br>
-        <div id="in-column1">first</div>
-    </div>
-    <br>
-    <div>
-        <div id="in-column2">second</div>
         <br>
         <br>
-        <div id="in-column3">third</div>
         <br>
+        <div id="outer3-inner2">sixth</div>
     </div>
 </div>
 
@@ -57,9 +75,12 @@ onclick = function(event) {
     shouldBe("event.offsetY", "event.expectedOffsetY");
 }
 
-onload = function() {
-    dispatchEvent(380, 500, 'in-column1', 79, 29);
-    dispatchEvent(480, 400, 'in-column2', 63, 29);
-    dispatchEvent(632, 321, 'in-column3', 99, 0);
+window.onload = function() {
+    dispatchEvent(330, 415, "outer1-inner1", 29, 44);
+    dispatchEvent(380, 365, "outer1-inner2", 29, 44);
+    dispatchEvent(446, 315, "outer2-inner1", 29, 44);
+    dispatchEvent(496, 265, "outer2-inner2", 29, 44);
+    dispatchEvent(562, 365, "outer3-inner1", 29, 44);
+    dispatchEvent(612, 415, "outer3-inner2", 29, 44);
 }
 </script>