Make RenderObject::style() return a const object

Source/core/page/EventHandler.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)
  *
  * 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.
@@ skipping 1037 matching lines @@
 #if OS(WIN)
     if (panScrollInProgress())
         return NoCursorChange;
 #endif
 
     Node* node = result.innerPossiblyPseudoNode();
     if (!node)
         return selectAutoCursor(result, node, iBeamCursor());
 
     LayoutObject* renderer = node->renderer();
-    LayoutStyle* style = renderer ? renderer->style() : nullptr;
+    const LayoutStyle* style = renderer ? renderer->style() : nullptr;
 
     if (renderer) {
         Cursor overrideCursor;
         switch (renderer->getCursor(roundedIntPoint(result.localPoint()), overrideCursor)) {
         case SetCursorBasedOnStyle:
             break;
         case SetCursor:
             return overrideCursor;
         case DoNotSetCursor:
             return NoCursorChange;
@@ skipping 2828 matching lines @@
 unsigned EventHandler::accessKeyModifiers()
 {
 #if OS(MACOSX)
     return PlatformEvent::CtrlKey | PlatformEvent::AltKey;
 #else
     return PlatformEvent::AltKey;
 #endif
 }
 
 } // namespace blink