Oilpan: move 2D Canvas and WebGL objects to the heap.

Source/bindings/core/v8/Nullable.h

Index: Source/bindings/core/v8/Nullable.h
diff --git a/Source/bindings/core/v8/Nullable.h b/Source/bindings/core/v8/Nullable.h
index 0f8356c472d399a03fad26c4fcbcda01f3f8ce64..acda9ad61e8f20ca0e16262996b6bf745725b1c0 100644
--- a/Source/bindings/core/v8/Nullable.h
+++ b/Source/bindings/core/v8/Nullable.h
@@ -5,12 +5,15 @@
 #ifndef Nullable_h
 #define Nullable_h
 
+#include "platform/heap/Handle.h"
 #include "wtf/Assertions.h"
+#include "wtf/TypeTraits.h"
 
 namespace WebCore {
 
 template <typename T>
 class Nullable {
+    DISALLOW_ALLOCATION();
 public:
     Nullable()
         : m_value()
@@ -41,7 +44,19 @@ public:
         return (m_isNull && other.m_isNull) || (!m_isNull && !other.m_isNull && m_value == other.m_value);
     }
 
+    template<typename U = T>
+    typename WTF::EnableIf<WTF::NeedsTracing<U>::value, void>::Type trace(Visitor* visitor)
+    {
+        visitor->trace(m_value);
+    }
+
 private:
+    // FIXME: Oilpan: the static analyser isn't (yet) able to
+    // spot the above trace() function template. When Nullable<>
+    // instantiations over traceable values are then processed,
+    // it'll report an error. A false negative; the trace() method
+    // is instantiated.
+    GC_PLUGIN_IGNORE("393465")
     T m_value;
     bool m_isNull;
 };