Added missing null check to avoid crash.

Source/core/html/forms/TextFieldInputType.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 214 matching lines @@
         if (event->defaultHandled())
             return;
     }
 
     if (element().renderer() && (event->isMouseEvent() || event->isDragEvent() || event->hasInterface(EventNames::WheelEvent) || event->type() == EventTypeNames::blur || event->type() == EventTypeNames::focus)) {
         RenderTextControlSingleLine* renderTextControl = toRenderTextControlSingleLine(element().renderer());
         if (event->type() == EventTypeNames::blur) {
             if (RenderBox* innerTextRenderer = element().innerTextElement()->renderBox()) {
                 // FIXME: This class has no need to know about RenderLayer!
                 if (RenderLayer* innerLayer = innerTextRenderer->layer()) {
-                    RenderLayerScrollableArea* innerScrollableArea = innerLayer->scrollableArea();
-                    IntSize scrollOffset(!renderTextControl->style()->isLeftToRightDirection() ? innerScrollableArea->scrollWidth() : 0, 0);
-                    innerScrollableArea->scrollToOffset(scrollOffset, ScrollOffsetClamped);
+                    if (RenderLayerScrollableArea* innerScrollableArea = innerLayer->scrollableArea()) {
+                        IntSize scrollOffset(!renderTextControl->style()->isLeftToRightDirection() ? innerScrollableArea->scrollWidth() : 0, 0);
+                        innerScrollableArea->scrollToOffset(scrollOffset, ScrollOffsetClamped);
+                    }
                 }
             }
 
             renderTextControl->capsLockStateMayHaveChanged();
         } else if (event->type() == EventTypeNames::focus) {
             renderTextControl->capsLockStateMayHaveChanged();
         }
 
         element().forwardEvent(event);
     }
@@ skipping 305 matching lines @@
     return shouldSpinButtonRespondToMouseEvents() && element().focused();
 }
 
 void TextFieldInputType::spinButtonDidReleaseMouseCapture(SpinButtonElement::EventDispatch eventDispatch)
 {
     if (eventDispatch == SpinButtonElement::EventDispatchAllowed)
         element().dispatchFormControlChangeEvent();
 }
 
 } // namespace WebCore