Remove RawPtr.h

third_party/WebKit/Source/platform/heap/BlinkGCAPIReference.md

 # Blink GC API reference
 
 This is a through document for Oilpan API usage.
 If you want to learn the API usage quickly, look at
 [this tutorial](https://docs.google.com/presentation/d/1XPu03ymz8W295mCftEC9KshH9Icxfq81YwIJQzQrvxo/edit#slide=id.p).
 
 [TOC]
 
 ## Header file
 
@@ skipping 213 matching lines @@
 
 ```c++
 void someFunction()
 {
     SomeGarbageCollectedClass* object = new SomeGarbageCollectedClass; // OK, retained by a pointer.
     ...
 }
 // OK to leave the object behind. The Blink GC system will free it up when it becomes unused.
 ```
 
-*** aside
-*Transitional only*
-
-`RawPtr<T>` is a simple wrapper of a raw pointer `T*` used in the transitional period.
-Most`RawPtr<T>`s will be replaced with raw pointers.
-
 ### Member, WeakMember
 
 In a garbage-collected class, on-heap objects must be retained by `Member<T>` or `WeakMember<T>`, depending on
 the desired semantics.
 
 `Member<T>` represents a *strong* reference to an object of type `T`, which means that the referred object is kept
 alive as long as the owner class instance is alive. Unlike `RefPtr<T>`, it is okay to form a reference cycle with
 members (in on-heap objects) and raw pointers (on stack).
 
 `WeakMember<T>` is a *weak* reference to an object of type `T`. Unlike `Member<T>`, `WeakMember<T>` does not keep
@@ skipping 132 matching lines @@
 DEFINE_TRACE(C)
 {
     visitor->trace(m_x);
     visitor->trace(m_y); // Weak member needs to be traced.
     visitor->trace(m_z); // Heap collection does, too.
     B::trace(visitor); // Delegate to the parent. In this case it's empty, but this is required.
 }
 ```
 
 ## Heap collections