Use refs for non-null GraphicsContext, Scrollbar, etc. in scrollbar related code

third_party/WebKit/Source/core/frame/LocalFrame.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Simon Hausmann <hausmann@kde.org>
  *                     2000 Stefan Schimanski <1Stein@gmx.de>
  *                     2001 George Staikos <staikos@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov <ap@nypop.com>
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 625 matching lines @@
     SkRect pictureBounds = SkRect::MakeIWH(paintingRect.width(), paintingRect.height());
     SkPictureBuilder pictureBuilder(pictureBounds);
     {
         GraphicsContext& paintContext = pictureBuilder.context();
 
         AffineTransform transform;
         transform.scale(deviceScaleFactor, deviceScaleFactor);
         transform.translate(-paintingRect.x(), -paintingRect.y());
         TransformRecorder transformRecorder(paintContext, displayItemClient, transform);
 
-        m_view->paintContents(&paintContext, globalPaintFlags, paintingRect);
+        m_view->paintContents(paintContext, globalPaintFlags, paintingRect);
 
     }
     RefPtr<const SkPicture> recording = pictureBuilder.endRecording();
     RefPtr<SkImage> skImage = adoptRef(SkImage::NewFromPicture(recording.get(),
         SkISize::Make(paintingRect.width(), paintingRect.height()), nullptr, nullptr));
     RefPtr<Image> image = StaticBitmapImage::create(skImage.release());
 
     return DragImage::create(image.get(), shouldRespectImageOrientation, deviceScaleFactor,
         InterpolationHigh, opacity);
 }
@@ skipping 267 matching lines @@
 {
     m_frame->disableNavigation();
 }
 
 FrameNavigationDisabler::~FrameNavigationDisabler()
 {
     m_frame->enableNavigation();
 }
 
 } // namespace blink