[wrapper-tracing] Redesign dispatching on non-inheriting cases

third_party/WebKit/Source/bindings/core/v8/TraceWrapperReference.md

 # Wrapper Tracing Reference
 
 This document describes wrapper tracing and how its API is supposed to be used.
 
 [TOC]
 
 ## Quickstart guide
 
 Wrapper tracing is used to represent reachability across V8 and Blink. The
 following checklist highlights the modifications needed to make a class
@@ skipping 239 matching lines @@
 ``A -> B -> C`` where both ``A`` and ``C`` are ``ScriptWrappable``s that
 need to be traced.
 
 In this case, the same rules as with ``ScriptWrappables`` apply, except for the
 difference that these classes need to inherit from ``TraceWrapperBase``.
 
 ### Memory-footprint critical uses
 
 In the case we cannot afford inheriting from ``TraceWrapperBase``, which will
 add a vtable pointer for tracing wrappers, use
-``DECLARE_TRACE_WRAPPERS_WITHOUT_BASE`` to declare a traceWrappers method.
+``DEFINE_TRAIT_FOR_TRACE_WRAPPERS(ClassName)`` after defining
+``ClassName`` to define the proper tracing specializations.
 
 ## Explicit write barriers
 
 Sometimes it is necessary to stick with the regular types and issue the write
 barriers explicitly. For example, if memory footprint is really important and
 it's not possible to use ``TraceWrapperMember`` which adds another pointer
 field. In this case, tracing needs to be adjusted to tell the system that all
 barriers will be done manually.
 
 ```c++
 class ManualWrappable : public ScriptWrappable {
  public:
   void setNew(OtherWrappable* newValue) {
     m_otherWrappable = newValue;
     SriptWrappableVisitor::writeBarrier(this, m_otherWrappable);
   }
 
   DECLARE_VIRTUAL_TRACE_WRAPPERS();
  private:
   Member<OtherWrappable>> m_otherWrappable;
 };
 
 DEFINE_TRACE_WRAPPERS(ManualWrappable) {
   for (auto other : m_otherWrappables)
     visitor->traceWrappersWithManualWriteBarrier(other);
 }
 ```