[ChromeDriver] Fix clicking a map area broken by blink change 180610.

chrome/test/chromedriver/js/get_element_region.js

 // Copyright (c) 2013 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.
 
 function getElementRegion(element) {
   // Check that node type is element.
   if (element.nodeType != 1)
     throw new Error(element + ' is not an element');
 
   // We try 2 methods to determine element region. Try the first client rect,
   // and then the bounding client rect.
   // SVG is one case that doesn't have a first client rect.
   var clientRects = element.getClientRects();
-  if (clientRects.length == 0) {
+
+  // Element area of a map has same first ClientRect and BoundingClientRect
+  // after blink roll at chromium commit position 290738 which includes blink
+  // revision 180610. Thus handle area as a special case.
+  if (clientRects.length == 0 || element.tagName.toLowerCase() == 'area') {
     var box = element.getBoundingClientRect();
     if (element.tagName.toLowerCase() == 'area') {
       var coords = element.coords.split(',');
       if (element.shape.toLowerCase() == 'rect') {
         if (coords.length != 4)
           throw new Error('failed to detect the region of the area');
         var leftX = Number(coords[0]);
         var topY = Number(coords[1]);
         var rightX = Number(coords[2]);
         var bottomY = Number(coords[3]);
@@ skipping 50 matching lines @@
     var clientRect = clientRects[0];
     var box = element.getBoundingClientRect();
     return {
         'left': clientRect.left - box.left,
         'top': clientRect.top - box.top,
         'width': clientRect.right - clientRect.left,
         'height': clientRect.bottom - clientRect.top
     };
   }
 }