Oilpan: use Member<> for FilterEffect's filter reference.

Source/platform/graphics/filters/SkiaImageFilterBuilder.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 23 matching lines @@
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/graphics/filters/FilterEffect.h"
 #include "platform/graphics/filters/FilterOperations.h"
 #include "platform/graphics/filters/SourceGraphic.h"
 #include "platform/graphics/skia/SkiaUtils.h"
 #include "public/platform/WebPoint.h"
 
 namespace blink {
 
 SkiaImageFilterBuilder::SkiaImageFilterBuilder()
-    : m_context(0)
-    , m_sourceGraphic(0)
+    : m_context(nullptr)
+    , m_sourceGraphic(nullptr)
 {
 }
 
 SkiaImageFilterBuilder::SkiaImageFilterBuilder(GraphicsContext* context)
     : m_context(context)
-    , m_sourceGraphic(0)
+    , m_sourceGraphic(nullptr)
 {
 }
 
 SkiaImageFilterBuilder::~SkiaImageFilterBuilder()
 {
 }
 
 PassRefPtr<SkImageFilter> SkiaImageFilterBuilder::build(FilterEffect* effect, ColorSpace colorSpace, bool destinationRequiresValidPreMultipliedPixels)
 {
     if (!effect)
@@ skipping 122 matching lines @@
         filters->appendReferenceFilter(filter.get());
     }
 }
 
 PassRefPtr<SkImageFilter> SkiaImageFilterBuilder::buildTransform(const AffineTransform& transform, SkImageFilter* input)
 {
     return adoptRef(SkMatrixImageFilter::Create(affineTransformToSkMatrix(transform), SkPaint::kHigh_FilterLevel, input));
 }
 
 } // namespace blink