Audit the use of UpdateStyleAndLayoutIgnorePendingStylesheets in FrameSelection::revealSelection

third_party/WebKit/Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 Apple 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 317 matching lines @@
     }
     m_frame->editor().respondToChangedSelection(oldSelectionInDOMTree, options);
     if (userTriggered == UserTriggered) {
         ScrollAlignment alignment;
 
         if (m_frame->editor().behavior().shouldCenterAlignWhenSelectionIsRevealed())
             alignment = (align == CursorAlignOnScroll::Always) ? ScrollAlignment::alignCenterAlways : ScrollAlignment::alignCenterIfNeeded;
         else
             alignment = (align == CursorAlignOnScroll::Always) ? ScrollAlignment::alignTopAlways : ScrollAlignment::alignToEdgeIfNeeded;
 
+        // TODO(xiaochengh): The use of updateStyleAndLayoutIgnorePendingStylesheets
+        // needs to be audited.  See http://crbug.com/590369 for more details.
+        document().updateStyleAndLayoutIgnorePendingStylesheets();
+
         revealSelection(alignment, RevealExtent);
     }
 
     notifyAccessibilityForSelectionChange();
     notifyCompositorForSelectionChange();
     notifyEventHandlerForSelectionChange();
     m_frame->localDOMWindow()->enqueueDocumentEvent(Event::create(EventTypeNames::selectionchange));
 }
 
 void FrameSelection::setSelection(const VisibleSelection& newSelection, SetSelectionOptions options, CursorAlignOnScroll align, TextGranularity granularity)
@@ skipping 797 matching lines @@
             return form;
     }
 
     // Try walking forward in the node tree to find a form element.
     return scanForForm(start);
 }
 
 void FrameSelection::revealSelection(const ScrollAlignment& alignment, RevealExtentOption revealExtentOption)
 {
     DCHECK(isAvailable());
-
-    // TODO(xiaochengh): The use of updateStyleAndLayoutIgnorePendingStylesheets
-    // needs to be audited.  See http://crbug.com/590369 for more details.
-    document().updateStyleAndLayoutIgnorePendingStylesheets();
+    DCHECK(!document().needsLayoutTreeUpdate());
 
     LayoutRect rect;
 
     switch (getSelectionType()) {
     case NoSelection:
         return;
     case CaretSelection:
         rect = LayoutRect(absoluteCaretBounds());
         break;
     case RangeSelection:
@@ skipping 210 matching lines @@
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
     else
         LOG(INFO) << "Cannot showTree for <null> FrameSelection.";
 }
 
 #endif