Automation API hit test should automatically convert to integer coordinates.

chrome/renderer/resources/extensions/automation/automation_node.js

 // Copyright 2014 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.
 
 var AutomationEvent = require('automationEvent').AutomationEvent;
 var automationInternal =
     require('binding').Binding.create('automationInternal').generate();
 var exceptionHandler = require('uncaught_exception_handler');
 var IsInteractPermitted =
     requireNative('automationInternal').IsInteractPermitted;
@@ skipping 380 matching lines @@
   getImageData: function(maxWidth, maxHeight) {
     this.performAction_('getImageData',
                         { maxWidth: maxWidth,
                           maxHeight: maxHeight });
   },
 
   hitTest: function(x, y, eventToFire) {
     // Convert from global to tree-relative coordinates.
     var location = GetLocation(this.treeID, GetRootID(this.treeID));
     this.performAction_('hitTest',
-                        { x: x - location.left,
-                          y: y - location.top,
+                        { x: Math.floor(x - location.left),
+                          y: Math.floor(y - location.top),
                           eventToFire: eventToFire });
   },
 
   makeVisible: function() {
     this.performAction_('makeVisible');
   },
 
   resumeMedia: function() {
     this.performAction_('resumeMedia');
   },
@@ skipping 753 matching lines @@
 utils.defineProperty(AutomationRootNode, 'getOrCreate', function(treeID) {
   return AutomationRootNodeImpl.getOrCreate(treeID);
 });
 
 utils.defineProperty(AutomationRootNode, 'destroy', function(treeID) {
   AutomationRootNodeImpl.destroy(treeID);
 });
 
 exports.$set('AutomationNode', AutomationNode);
 exports.$set('AutomationRootNode', AutomationRootNode);