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

third_party/WebKit/Source/web/WebPluginContainerImpl.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2014 Opera Software ASA. 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 96 matching lines @@
     Widget::setFrameRect(frameRect);
     reportGeometry();
 }
 
 void WebPluginContainerImpl::layoutIfNeeded()
 {
     RELEASE_ASSERT(m_webPlugin);
     m_webPlugin->layoutIfNeeded();
 }
 
-void WebPluginContainerImpl::paint(GraphicsContext* context, const CullRect& cullRect) const
+void WebPluginContainerImpl::paint(GraphicsContext& context, const CullRect& cullRect) const
 {
     if (!parent())
         return;
 
     // Don't paint anything if the plugin doesn't intersect.
     if (!cullRect.intersectsCullRect(frameRect()))
         return;
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*context, *m_element->layoutObject(), DisplayItem::Type::WebPlugin, LayoutPoint()))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(context, *m_element->layoutObject(), DisplayItem::Type::WebPlugin, LayoutPoint()))
         return;
 
-    LayoutObjectDrawingRecorder drawingRecorder(*context, *m_element->layoutObject(), DisplayItem::Type::WebPlugin, cullRect.m_rect, LayoutPoint());
-    context->save();
+    LayoutObjectDrawingRecorder drawingRecorder(context, *m_element->layoutObject(), DisplayItem::Type::WebPlugin, cullRect.m_rect, LayoutPoint());
+    context.save();
 
     ASSERT(parent()->isFrameView());
     FrameView* view =  toFrameView(parent());
 
     // The plugin is positioned in the root frame's coordinates, so it needs to
     // be painted in them too.
     IntPoint origin = view->contentsToRootFrame(IntPoint(0, 0));
-    context->translate(static_cast<float>(-origin.x()), static_cast<float>(-origin.y()));
+    context.translate(static_cast<float>(-origin.x()), static_cast<float>(-origin.y()));
 
-    WebCanvas* canvas = context->canvas();
+    WebCanvas* canvas = context.canvas();
 
     IntRect windowRect = view->contentsToRootFrame(cullRect.m_rect);
     m_webPlugin->paint(canvas, windowRect);
 
-    context->restore();
+    context.restore();
 }
 
 void WebPluginContainerImpl::invalidateRect(const IntRect& rect)
 {
     if (!parent())
         return;
 
     LayoutBox* layoutObject = toLayoutBox(m_element->layoutObject());
     if (!layoutObject)
         return;
@@ skipping 818 matching lines @@
         // frame view.
         computeClipRectsForPlugin(m_element, windowRect, clipRect, unobscuredRect);
     }
     getPluginOcclusions(m_element, this->parent(), frameRect(), cutOutRects);
     // Convert to the plugin position.
     for (size_t i = 0; i < cutOutRects.size(); i++)
         cutOutRects[i].move(-frameRect().x(), -frameRect().y());
 }
 
 } // namespace blinkf