Update textinput_helper.js to support subpixel coordinates

Update the textinput_helper.js text helper to support subpixel
precision for element coordinates.

R=nona@chromium.org

Review URL: https://codereview.chromium.org/309303002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274594 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/data/textinput/textinput_helper.js

@@ -4,8 +4,10 @@
 var textinput_helper = {
   retrieveElementCoordinate: function(id) {
     var ele = document.getElementById(id);
-    var coordinate = ele.offsetLeft + ',' + ele.offsetTop + ',' +
-        ele.offsetWidth + ',' + ele.offsetHeight;
+    var coordinate = Math.floor(ele.offsetLeft) + ',' +
+        Math.floor(ele.offsetTop) + ',' +
+        Math.ceil(ele.offsetWidth) + ',' +
+        Math.ceil(ele.offsetHeight);
     window.domAutomationController.send(coordinate);
   }
 };