DevTools: cleanup occurences of selection.getRangeAt to avoid NPE

third_party/WebKit/Source/devtools/front_end/ui/TextPrompt.js

 /*
  * Copyright (C) 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 374 matching lines @@
     },
 
     /**
      * @param {boolean=} force
      * @param {boolean=} reverse
      */
     complete: function(force, reverse)
     {
         this.clearAutoComplete(true);
         var selection = this._element.getComponentSelection();
-        if (!selection.rangeCount)
+        var selectionRange = selection && selection.rangeCount ? selection.getRangeAt(0) : null;
+        if (!selectionRange)
             return;
 
-        var selectionRange = selection.getRangeAt(0);
         var shouldExit;
 
         if (!force && !this.isCaretAtEndOfPrompt() && !this.isSuggestBoxVisible())
             shouldExit = true;
         else if (!selection.isCollapsed)
             shouldExit = true;
         else if (!force) {
             // BUG72018: Do not show suggest box if caret is followed by a non-stop character.
             var wordSuffixRange = selectionRange.startContainer.rangeOfWord(selectionRange.endOffset, this._completionStopCharacters, this._element, "forward");
             if (wordSuffixRange.toString().length)
@@ skipping 268 matching lines @@
     {
         return this._element.isInsertionCaretInside();
     },
 
     /**
      * @return {boolean}
      */
     isCaretAtEndOfPrompt: function()
     {
         var selection = this._element.getComponentSelection();
-        if (!selection.rangeCount || !selection.isCollapsed)
+        var selectionRange = selection && selection.rangeCount ? selection.getRangeAt(0) : null;
+        if (!selectionRange || !selection.isCollapsed)
             return false;
 
-        var selectionRange = selection.getRangeAt(0);
         var node = selectionRange.startContainer;
         if (!node.isSelfOrDescendant(this._element))
             return false;
 
         if (node.nodeType === Node.TEXT_NODE && selectionRange.startOffset < node.nodeValue.length)
             return false;
 
         var foundNextText = false;
         while (node) {
             if (node.nodeType === Node.TEXT_NODE && node.nodeValue.length) {
@@ skipping 288 matching lines @@
 
             return;
         }
 
         WebInspector.TextPrompt.prototype.onKeyDown.apply(this, arguments);
     },
 
     __proto__: WebInspector.TextPrompt.prototype
 }