Fix collision calculation

chrome/browser/resources/options/chromeos/display_layout.js

 // Copyright 2016 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.
 
 cr.exportPath('options');
 
 /**
  * Enumeration of display layout. These values must match the C++ values in
  * ash::DisplayController.
  * @enum {number}
@@ skipping 377 matching lines @@
      *     0 means snap from any distance.
      * @return {number}
      */
     snapToY: function(y, parentDiv, opt_snapDistance) {
       return snapToEdge_(
           y, this.div.offsetHeight, parentDiv.offsetTop, parentDiv.offsetHeight,
           opt_snapDistance);
     },
 
     /**
-     * Intersects this.div with |otherDiv|. If there is a collision, modifies
-     * |deltaPos| to limit movement to a single axis and avoid the collision
-     * and returns true.
+     * Intersects this.div at |pos| with |otherDiv|. If there is a collision,
+     * modifies |deltaPos| to limit movement to a single axis and avoid the
+     * collision and returns true.
+     * @param {!options.DisplayPosition} pos
      * @param {?HTMLElement} otherDiv
      * @param {!options.DisplayPosition} deltaPos
      * @return {boolean} Whether there was a collision.
      */
-    collideWithDivAndModifyDelta: function(otherDiv, deltaPos) {
+    collideWithDivAndModifyDelta: function(pos, otherDiv, deltaPos) {
       var div = this.div;
-      var newX = div.offsetLeft + deltaPos.x;
-      var newY = div.offsetTop + deltaPos.y;
+      var newX = pos.x + deltaPos.x;
+      var newY = pos.y + deltaPos.y;
 
       if ((newX + div.offsetWidth <= otherDiv.offsetLeft) ||
           (newX >= otherDiv.offsetLeft + otherDiv.offsetWidth) ||
           (newY + div.offsetHeight <= otherDiv.offsetTop) ||
           (newY >= otherDiv.offsetTop + otherDiv.offsetHeight)) {
         return false;
       }
 
       if (Math.abs(deltaPos.x) > Math.abs(deltaPos.y)) {
         if (deltaPos.x > 0) {
           var x = otherDiv.offsetLeft - div.offsetWidth;
-          if (x > div.offsetLeft)
-            deltaPos.x = x - div.offsetLeft;
+          if (x > pos.x)
+            deltaPos.x = x - pos.x;
           else
             deltaPos.x = 0;
         } else {
           var x = otherDiv.offsetLeft + otherDiv.offsetWidth;
-          if (x < div.offsetLeft)
-            deltaPos.x = x - div.offsetLeft;
+          if (x < pos.x)
+            deltaPos.x = x - pos.x;
           else
             deltaPos.x = 0;
         }
         deltaPos.y = 0;
       } else {
         deltaPos.x = 0;
         if (deltaPos.y > 0) {
           var y = otherDiv.offsetTop - div.offsetHeight;
-          if (y > div.offsetTop)
-            deltaPos.y = y - div.offsetTop;
+          if (y > pos.y)
+            deltaPos.y = y - pos.y;
           else
             deltaPos.y = 0;
         } else if (deltaPos.y < 0) {
           var y = otherDiv.offsetTop + otherDiv.offsetTop;
-          if (y < div.offsetTop)
-            deltaPos.y = y - div.offsetTop;
+          if (y < pos.y)
+            deltaPos.y = y - pos.y;
           else
             deltaPos.y = 0;
         }
       }
 
       return true;
     }
   };
 
   // Export
   return {DisplayLayout: DisplayLayout};
 });