Expand FrameSeleciton::base() to increase chances of hoisting update layout

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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
@@ skipping 567 matching lines @@
       TypingCommand::TextCompositionUpdate);
   // Event handlers might destroy document.
   if (!isAvailable())
     return;
 
   // TODO(yosin): The use of updateStyleAndLayoutIgnorePendingStylesheets
   // needs to be audited. see http://crbug.com/590369 for more details.
   document().updateStyleAndLayoutIgnorePendingStylesheets();
 
   // Find out what node has the composition now.
-  Position base = mostForwardCaretPosition(frame().selection().base());
+  Position base = mostForwardCaretPosition(
+      frame().selection().computeVisibleSelectionInDOMTree().base());
   Node* baseNode = base.anchorNode();
   if (!baseNode || !baseNode->isTextNode())
     return;
 
   Position extent = frame().selection().extent();
   Node* extentNode = extent.anchorNode();
 
   unsigned extentOffset = extent.computeOffsetInContainerNode();
   unsigned baseOffset = base.computeOffsetInContainerNode();
 
@@ skipping 520 matching lines @@
   finishComposingText(DoNotKeepSelection);
 }
 
 DEFINE_TRACE(InputMethodController) {
   visitor->trace(m_frame);
   visitor->trace(m_compositionRange);
   SynchronousMutationObserver::trace(visitor);
 }
 
 }  // namespace blink