MD History: Fix text selection in history items

chrome/browser/resources/md_history/history_item.js

 // Copyright 2015 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.
 
 /**
  * @param {!Element} root
  * @param {?Element} boundary
  * @param {cr.ui.FocusRow.Delegate} delegate
  * @constructor
  * @extends {cr.ui.FocusRow}
@@ skipping 115 matching lines @@
 
       numberOfItems: Number,
 
       // Search term used to obtain this history-item.
       searchTerm: String,
     },
 
     /** @private {?HistoryFocusRow} */
     row_: null,
 
+    /** @private {boolean} */
+    mouseDown_: false,
+
     /** @override */
     attached: function() {
       Polymer.RenderStatus.afterNextRender(this, function() {
         this.row_ = new HistoryFocusRow(
             this.$['main-container'], null, new FocusRowDelegate(this));
         this.row_.makeActive(this.ironListTabIndex == 0);
         this.listen(this, 'focus', 'onFocus_');
         this.listen(this, 'dom-change', 'onDomChange_');
       });
     },
 
     /** @override */
     detached: function() {
       this.unlisten(this, 'focus', 'onFocus_');
       this.unlisten(this, 'dom-change', 'onDomChange_');
       if (this.row_)
         this.row_.destroy();
     },
 
     /**
      * @private
      */
     onFocus_: function() {
+      // Don't change the focus while the mouse is down, as it prevents text
+      // selection. Not changing focus here is acceptable because the checkbox
+      // will be focused in onItemClick_() anyway.
+      if (this.mouseDown_)
+        return;
+
       if (this.lastFocused)
         this.row_.getEquivalentElement(this.lastFocused).focus();
       else
         this.row_.getFirstFocusable().focus();
 
       this.tabIndex = -1;
     },
 
     /**
      * @private
@@ skipping 34 matching lines @@
         index: this.index,
         shiftKey: e.shiftKey,
       });
     },
 
     /**
      * @param {MouseEvent} e
      * @private
      */
     onItemMousedown_: function(e) {
+      this.mouseDown_ = true;
+      listenOnce(document, 'mouseup', function() {
+        this.mouseDown_ = false;
+      }.bind(this));
       // Prevent shift clicking a checkbox from selecting text.
       if (e.shiftKey)
         e.preventDefault();
     },
 
     /**
      * @private
      * @return {string}
      */
     getEntrySummary_: function() {
@@ skipping 112 matching lines @@
    */
   HistoryItem.searchResultsTitle = function(numberOfResults, searchTerm) {
     var resultId = numberOfResults == 1 ? 'searchResult' : 'searchResults';
     return loadTimeData.getStringF(
         'foundSearchResults', numberOfResults, loadTimeData.getString(resultId),
         searchTerm);
   };
 
   return {HistoryItem: HistoryItem};
 });