New SELECT Popup: Do not select and scroll to an option of which visible area is less than 1px heig…

third_party/WebKit/Source/web/resources/listPicker.js

 "use strict";
 // Copyright (c) 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 global = {
     argumentsReceived: false,
     params: null,
     picker: null
 };
@@ skipping 69 matching lines @@
 ListPicker.prototype._handleWindowMessage = function(event) {
     eval(event.data);
     if (window.updateData.type === "update") {
         this._config.baseStyle = window.updateData.baseStyle;
         this._config.children = window.updateData.children;
         this._update();
     }
     delete window.updateData;
 };
 
+// This should be matched to the border width of the internal listbox
+// SELECT. See listPicker.css and html.css.
+ListPicker.ListboxSelectBorder = 1;
+
 ListPicker.prototype._handleWindowMouseMove = function (event) {
+    var visibleTop = ListPicker.ListboxSelectBorder;
+    var visibleBottom = this._selectElement.offsetHeight - ListPicker.ListboxSelectBorder;
+    var optionBounds = event.target.getBoundingClientRect();
+    if (optionBounds.height >= 1.0) {
+        // If the height of the visible part of event.target is less than 1px,
+        // ignore this event because it may be an error by sub-pixel layout.
+        if (optionBounds.top < visibleTop) {
+            if (optionBounds.bottom - visibleTop < 1.0)
+                return;
+        } else if (optionBounds.bottom > visibleBottom) {
+            if (visibleBottom - optionBounds.top < 1.0)
+                return;
+        }
+    }
     this.lastMousePositionX = event.clientX;
     this.lastMousePositionY = event.clientY;
     this._highlightOption(event.target);
     this._selectionSetByMouseHover = true;
     // Prevent the select element from firing change events for mouse input.
     event.preventDefault();
 };
 
 ListPicker.prototype._handleMouseUp = function(event) {
     if (event.target.tagName !== "OPTION")
@@ skipping 86 matching lines @@
         setTimeout(function () {
             window.pagePopupController.closePopup();
         }, 0);
         event.preventDefault();
     }
 };
 
 ListPicker.prototype._fixWindowSize = function() {
     this._selectElement.style.height = "";
     var maxHeight = this._selectElement.offsetHeight;
-    // heightOutsideOfContent should be matched to border widths of the listbox
-    // SELECT. See listPicker.css and html.css.
-    var heightOutsideOfContent = 2;
-    var noScrollHeight = Math.round(this._calculateScrollHeight() + heightOutsideOfContent);
+    var noScrollHeight = Math.round(this._calculateScrollHeight() + ListPicker.ListboxSelectBorder * 2);
     var desiredWindowHeight = noScrollHeight;
     var desiredWindowWidth = this._selectElement.offsetWidth;
     var expectingScrollbar = false;
     if (desiredWindowHeight > maxHeight) {
         desiredWindowHeight = maxHeight;
         // Setting overflow to auto does not increase width for the scrollbar
         // so we need to do it manually.
         desiredWindowWidth += getScrollbarWidth();
         expectingScrollbar = true;
     }
@@ skipping 210 matching lines @@
     }
     this._applyItemStyle(element, config.style);
 };
 
 if (window.dialogArguments) {
     initialize(dialogArguments);
 } else {
     window.addEventListener("message", handleMessage, false);
     window.setTimeout(handleArgumentsTimeout, 1000);
 }