Add documentation for platform/bindings

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).
 If you're just interested in wrapper tracing,
-see [Wrapper Tracing Reference](../../bindings/core/v8/TraceWrapperReference.md).
+see [Wrapper Tracing Reference](../bindings/TraceWrapperReference.md).
 
 [TOC]
 
 ## Header file
 
 Unless otherwise noted, any of the primitives explained in this page requires the following `#include` statement:
 
 ```c++
 #include "platform/heap/Handle.h"
 ```
@@ skipping 466 matching lines @@
 };
 ```
 
 Please be very cautious if you want to use a heap collection from multiple threads. Reference to heap collections may be passed to another thread using CrossThreadPersistents, but *you may not modify the collection from the non-owner thread*. This is because modifications to collections may trigger backing store reallocations, and Oilpan's per thread heap requires that modifications to a heap happen on its owner thread.
 
 ### Weak collections
 
 You can put `WeakMember<T>` in heap collections except for `HeapVector` and `HeapDeque` which we do not support.
 
 During an Oilpan GC, the weak members that refernce a collected object will be removed from its heap collection, meaning the size of the collection will shrink and you do not have to check for null weak members when iterating through the collection.