Keep the selection of the text field when changed by JS.

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 281 matching lines @@
         if (m_frame->editor().behavior().shouldCenterAlignWhenSelectionIsRevealed())
             alignment = (align == AlignCursorOnScrollAlways) ? ScrollAlignment::alignCenterAlways : ScrollAlignment::alignCenterIfNeeded;
         else
             alignment = (align == AlignCursorOnScrollAlways) ? ScrollAlignment::alignTopAlways : ScrollAlignment::alignToEdgeIfNeeded;
 
         revealSelection(alignment, RevealExtent);
     }
 
     notifyAccessibilityForSelectionChange();
     notifyCompositorForSelectionChange();
+    notifyEventHandlerForSelectionChange();
     m_frame->localDOMWindow()->enqueueDocumentEvent(Event::create(EventTypeNames::selectionchange));
 }
 
 static bool removingNodeRemovesPosition(Node& node, const Position& position)
 {
     if (!position.anchorNode())
         return false;
 
     if (position.anchorNode() == node)
         return true;
@@ skipping 1141 matching lines @@
 }
 
 void FrameSelection::notifyCompositorForSelectionChange()
 {
     if (!RuntimeEnabledFeatures::compositedSelectionUpdateEnabled())
         return;
 
     scheduleVisualUpdate();
 }
 
+void FrameSelection::notifyEventHandlerForSelectionChange()
+{
+    m_frame->eventHandler().notifySelectionChanged();
+}
+
 void FrameSelection::focusedOrActiveStateChanged()
 {
     bool activeAndFocused = isFocusedAndActive();
 
     RefPtrWillBeRawPtr<Document> document = m_frame->document();
     document->updateRenderTreeIfNeeded();
 
     // Because LayoutObject::selectionBackgroundColor() and
     // LayoutObject::selectionForegroundColor() check if the frame is active,
     // we have to update places those colors were painted.
@@ skipping 476 matching lines @@
     sel.showTreeForThis();
 }
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
 }
 
 #endif