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

Source/core/rendering/svg/RenderSVGInlineText.cpp

Index: Source/core/rendering/svg/RenderSVGInlineText.cpp
diff --git a/Source/core/rendering/svg/RenderSVGInlineText.cpp b/Source/core/rendering/svg/RenderSVGInlineText.cpp
index 1141a56d1c09a97a9656eeedff230845d20d5554..521d6a5ccddf682c814cc13cf29d4c50026ffa52 100644
--- a/Source/core/rendering/svg/RenderSVGInlineText.cpp
+++ b/Source/core/rendering/svg/RenderSVGInlineText.cpp
@@ -219,10 +219,9 @@ void RenderSVGInlineText::computeNewScaledFontForStyle(RenderObject* renderer, c
     ASSERT(style);
     ASSERT(renderer);
 
-    Document* document = renderer->document();
-    ASSERT(document);
+    Document& document = renderer->document();
 
-    StyleResolver* styleResolver = document->styleResolver();
+    StyleResolver* styleResolver = document.styleResolver();
     ASSERT(styleResolver);
 
     // Alter font-size to the right on-screen value to avoid scaling the glyphs themselves, except when GeometricPrecision is specified.
@@ -239,7 +238,7 @@ void RenderSVGInlineText::computeNewScaledFontForStyle(RenderObject* renderer, c
     FontDescription fontDescription(style->fontDescription());
 
     // FIXME: We need to better handle the case when we compute very small fonts below (below 1pt).
-    fontDescription.setComputedSize(FontSize::getComputedSizeFromSpecifiedSize(document, scalingFactor, fontDescription.isAbsoluteSize(), fontDescription.specifiedSize(), DoNotUseSmartMinimumForFontSize));
+    fontDescription.setComputedSize(FontSize::getComputedSizeFromSpecifiedSize(&document, scalingFactor, fontDescription.isAbsoluteSize(), fontDescription.specifiedSize(), DoNotUseSmartMinimumForFontSize));
 
     scaledFont = Font(fontDescription, 0, 0);
     scaledFont.update(styleResolver->fontSelector());