Oilpan: Remove OffHeapCollectionTrait

Source/core/css/CSSGradientValue.cpp

 /*
  * Copyright (C) 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2015 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 553 matching lines @@
     ASSERT(object);
     for (auto& stop : m_stops) {
         if (!stop.isHint() && resolveStopColor(stop.m_color.get(), *object).hasAlpha())
             return false;
     }
     return true;
 }
 
 DEFINE_TRACE_AFTER_DISPATCH(CSSGradientValue)
 {
+#if ENABLE(OILPAN)
     visitor->trace(m_firstX);
     visitor->trace(m_firstY);
     visitor->trace(m_secondX);
     visitor->trace(m_secondY);
     visitor->trace(m_stops);
+#endif
     CSSImageGeneratorValue::traceAfterDispatch(visitor);
 }
 
 String CSSLinearGradientValue::customCSSText() const
 {
     StringBuilder result;
     if (m_gradientType == CSSDeprecatedLinearGradient) {
         result.appendLiteral("-webkit-gradient(linear, ");
         result.append(m_firstX->cssText());
         result.append(' ');
@@ skipping 613 matching lines @@
     visitor->trace(m_firstRadius);
     visitor->trace(m_secondRadius);
     visitor->trace(m_shape);
     visitor->trace(m_sizingBehavior);
     visitor->trace(m_endHorizontalSize);
     visitor->trace(m_endVerticalSize);
     CSSGradientValue::traceAfterDispatch(visitor);
 }
 
 } // namespace blink