Fix bug on Android causing composition underlines to appear in the wrong place

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 602 matching lines @@
   setEditableSelectionOffsets(selectedRange, NotUserTriggered);
 
   if (underlines.isEmpty()) {
     document().markers().addCompositionMarker(
         m_compositionRange->startPosition(), m_compositionRange->endPosition(),
         Color::black, false,
         LayoutTheme::theme().platformDefaultCompositionBackgroundColor());
     return;
   }
 
-  addCompositionUnderlines(underlines, baseNode->parentNode(), baseOffset);
+  const PlainTextRange compositionPlainTextRange =
+      PlainTextRange::create(*baseNode->parentNode(), *m_compositionRange);
+  addCompositionUnderlines(underlines, baseNode->parentNode(),
+                           compositionPlainTextRange.start());
 }
 
 PlainTextRange InputMethodController::createSelectionRangeForSetComposition(
     int selectionStart,
     int selectionEnd,
     size_t textLength) const {
   const int selectionOffsetsStart =
       static_cast<int>(getSelectionOffsets().start());
   const int start = selectionOffsetsStart + selectionStart;
   const int end = selectionOffsetsStart + selectionEnd;
@@ skipping 485 matching lines @@
   finishComposingText(DoNotKeepSelection);
 }
 
 DEFINE_TRACE(InputMethodController) {
   visitor->trace(m_frame);
   visitor->trace(m_compositionRange);
   SynchronousMutationObserver::trace(visitor);
 }
 
 }  // namespace blink