Revert of Content in disabled input field should not be selectable.

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  * Copyright (C) 2015 Google 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:
@@ skipping 828 matching lines @@
     const HitTestResult& hitTestResult) {
   if (!selection().isAvailable())
     return false;
   if (hitTestResult.isLiveLink())
     return false;
 
   Node* innerNode = hitTestResult.innerNode();
   if (!innerNode)
     return false;
   innerNode->document().updateStyleAndLayoutTree();
-  bool innerNodeIsSelectable =
-      hasEditableStyle(*innerNode) || innerNode->canStartSelection();
+  bool innerNodeIsSelectable = hasEditableStyle(*innerNode) ||
+                               innerNode->isTextNode() ||
+                               innerNode->canStartSelection();
   if (!innerNodeIsSelectable)
     return false;
 
   selectClosestWordFromHitTestResult(hitTestResult,
                                      AppendTrailingWhitespace::DontAppend,
                                      SelectInputEventType::Touch);
   if (!selection().isAvailable()) {
     // "editing/selection/longpress-selection-in-iframe-removed-crash.html"
     // reach here.
     return false;
@@ skipping 104 matching lines @@
   return event.event().altKey() && event.isOverLink();
 }
 
 bool isExtendingSelection(const MouseEventWithHitTestResults& event) {
   bool isMouseDownOnLinkOrImage =
       event.isOverLink() || event.hitTestResult().image();
   return event.event().shiftKey() && !isMouseDownOnLinkOrImage;
 }
 
 }  // namespace blink