Fix more null-checks in SVGLengthContext::convertValueFrom*

third_party/WebKit/Source/core/svg/SVGLengthContext.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 355 matching lines @@
     default:
       break;
   }
 
   ASSERT_NOT_REACHED();
   return 0;
 }
 
 float SVGLengthContext::convertValueFromUserUnitsToCHS(float value) const {
   const ComputedStyle* style = computedStyleForLengthResolving(m_context);
+  if (!style)
+    return 0;
   const SimpleFontData* fontData = style->font().primaryFont();
-  if (!style || !fontData)
+  if (!fontData)
     return 0;
-
   float zeroWidth =
       fontData->getFontMetrics().zeroWidth() / style->effectiveZoom();
   if (!zeroWidth)
     return 0;
-
   return value / zeroWidth;
 }
 
 float SVGLengthContext::convertValueFromCHSToUserUnits(float value) const {
   const ComputedStyle* style = computedStyleForLengthResolving(m_context);
   if (!style)
     return 0;
-
   const SimpleFontData* fontData = style->font().primaryFont();
   if (!fontData)
     return 0;
-
   return value * fontData->getFontMetrics().zeroWidth() /
          style->effectiveZoom();
 }
 
 float SVGLengthContext::convertValueFromUserUnitsToEXS(float value) const {
   const ComputedStyle* style = computedStyleForLengthResolving(m_context);
+  if (!style)
+    return 0;
   const SimpleFontData* fontData = style->font().primaryFont();
-  if (!style || !fontData)
+  if (!fontData)
     return 0;
-
   // Use of ceil allows a pixel match to the W3Cs expected output of
   // coords-units-03-b.svg, if this causes problems in real world cases maybe it
   // would be best to remove this.
   float xHeight =
       ceilf(fontData->getFontMetrics().xHeight() / style->effectiveZoom());
   if (!xHeight)
     return 0;
-
   return value / xHeight;
 }
 
 float SVGLengthContext::convertValueFromEXSToUserUnits(float value) const {
   const ComputedStyle* style = computedStyleForLengthResolving(m_context);
+  if (!style)
+    return 0;
   const SimpleFontData* fontData = style->font().primaryFont();
-  if (!style || !fontData)
+  if (!fontData)
     return 0;
-
   // Use of ceil allows a pixel match to the W3Cs expected output of
   // coords-units-03-b.svg, if this causes problems in real world cases maybe it
   // would be best to remove this.
   return value *
          ceilf(fontData->getFontMetrics().xHeight() / style->effectiveZoom());
 }
 
 bool SVGLengthContext::determineViewport(FloatSize& viewportSize) const {
   if (!m_context)
     return false;
@@ skipping 26 matching lines @@
   const ComputedStyle* rootStyle = rootElementStyle(m_context);
   if (!rootStyle)
     return 0;
 
   CSSToLengthConversionData conversionData = CSSToLengthConversionData(
       style, rootStyle, m_context->document().layoutViewItem(), 1.0f);
   Length length = primitiveValue.convertToLength(conversionData);
   return valueForLength(length, 1.0f, mode);
 }
 }  // namespace blink