Merge 105261 - Web Inspector: Popover does not disappear, causes debugger failure.

Source/WebCore/inspector/front-end/JavaScriptSourceFrame.js

Index: Source/WebCore/inspector/front-end/JavaScriptSourceFrame.js
===================================================================
--- Source/WebCore/inspector/front-end/JavaScriptSourceFrame.js	(revision 105593)
+++ Source/WebCore/inspector/front-end/JavaScriptSourceFrame.js	(working copy)
@@ -300,14 +300,18 @@
         var highlightElement = this._highlightElement;
         if (!highlightElement)
             return;
+        // FIXME: the text editor should maintain highlight on its own. The check below is a workaround for
+        // the case when highlight element is detached from DOM by the TextViewer when re-building the DOM.
         var parentElement = highlightElement.parentElement;
-        var child = highlightElement.firstChild;
-        while (child) {
-            var nextSibling = child.nextSibling;
-            parentElement.insertBefore(child, highlightElement);
-            child = nextSibling;
+        if (parentElement) {
+            var child = highlightElement.firstChild;
+            while (child) {
+                var nextSibling = child.nextSibling;
+                parentElement.insertBefore(child, highlightElement);
+                child = nextSibling;
+            }
+            parentElement.removeChild(highlightElement);
         }
-        parentElement.removeChild(highlightElement);
         delete this._highlightElement;
         RuntimeAgent.releaseObjectGroup(this._popoverObjectGroup);
     },