Have Node::document() return a reference instead of a pointer

Source/core/rendering/RenderImage.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011-2012. All rights reserved.
  *
@@ skipping 154 matching lines @@
     if (!m_didIncrementVisuallyNonEmptyPixelCount) {
         // At a zoom level of 1 the image is guaranteed to have an integer size.
         view()->frameView()->incrementVisuallyNonEmptyPixelCount(flooredIntSize(m_imageResource->imageSize(1.0f)));
         m_didIncrementVisuallyNonEmptyPixelCount = true;
     }
 
     bool imageSizeChanged = false;
 
     // Set image dimensions, taking into account the size of the alt text.
     if (m_imageResource->errorOccurred() || !newImage) {
-        if (!m_altText.isEmpty() && document()->hasPendingStyleRecalc()) {
+        if (!m_altText.isEmpty() && document().hasPendingStyleRecalc()) {
             ASSERT(node());
             if (node()) {
                 m_needsToSetSizeForAltText = true;
                 node()->setNeedsStyleRecalc(LocalStyleChange, StyleChangeFromRenderer);
             }
             return;
         }
         imageSizeChanged = setImageSizeForAltText(m_imageResource->cachedImage());
     }
 
@@ skipping 160 matching lines @@
                     centerX = 0;
                 LayoutUnit centerY = (usableHeight - imageSize.height()) / 2;
                 if (centerY < 0)
                     centerY = 0;
                 imageOffset = LayoutSize(leftBorder + leftPad + centerX + borderWidth, topBorder + topPad + centerY + borderWidth);
                 context->drawImage(image.get(), pixelSnappedIntRect(LayoutRect(paintOffset + imageOffset, imageSize)), CompositeSourceOver, shouldRespectImageOrientation());
                 errorPictureDrawn = true;
             }
 
             if (!m_altText.isEmpty()) {
-                String text = document()->displayStringModifiedByEncoding(m_altText);
+                String text = document().displayStringModifiedByEncoding(m_altText);
                 const Font& font = style()->font();
                 const FontMetrics& fontMetrics = font.fontMetrics();
                 LayoutUnit ascent = fontMetrics.ascent();
                 LayoutPoint textRectOrigin = paintOffset;
                 textRectOrigin.move(leftBorder + leftPad + (paddingWidth / 2) - borderWidth, topBorder + topPad + (paddingHeight / 2) - borderWidth);
                 LayoutPoint textOrigin(textRectOrigin.x(), textRectOrigin.y() + ascent);
 
                 // Only draw the alt text if it'll fit within the content box,
                 // and only if it fits above the error image.
                 TextRun textRun = RenderBlock::constructTextRun(this, font, text, style());
@@ skipping 46 matching lines @@
 void RenderImage::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     RenderReplaced::paint(paintInfo, paintOffset);
 
     if (paintInfo.phase == PaintPhaseOutline)
         paintAreaElementFocusRing(paintInfo);
 }
 
 void RenderImage::paintAreaElementFocusRing(PaintInfo& paintInfo)
 {
-    Document* document = this->document();
+    Document& document = this->document();
 
-    if (document->printing() || !document->frame()->selection()->isFocusedAndActive())
+    if (document.printing() || !document.frame()->selection()->isFocusedAndActive())
         return;
 
     if (paintInfo.context->paintingDisabled() && !paintInfo.context->updatingControlTints())
         return;
 
-    Element* focusedElement = document->focusedElement();
+    Element* focusedElement = document.focusedElement();
     if (!focusedElement || !isHTMLAreaElement(focusedElement))
         return;
 
     HTMLAreaElement* areaElement = toHTMLAreaElement(focusedElement);
     if (areaElement->imageElement() != node())
         return;
 
     // Even if the theme handles focus ring drawing for entire elements, it won't do it for
     // an area within an image, so we don't call RenderTheme::supportsFocusRing here.
 
@@ skipping 174 matching lines @@
         return 0;
 
     ImageResource* cachedImage = m_imageResource->cachedImage();
     if (cachedImage && cachedImage->image() && cachedImage->image()->isSVGImage())
         return static_cast<SVGImage*>(cachedImage->image())->embeddedContentBox();
 
     return 0;
 }
 
 } // namespace WebCore