Add documentation for platform/bindings

third_party/WebKit/Source/platform/bindings/DOMWrapperMap.h

 /*
  * Copyright (C) 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 24 matching lines @@
 
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/bindings/WrapperTypeInfo.h"
 #include "platform/wtf/Compiler.h"
 #include "platform/wtf/HashMap.h"
 #include "v8/include/v8-util.h"
 #include "v8/include/v8.h"
 
 namespace blink {
 
+// Used to store and maintain a mapping between C++ objects and JavaScript
+// wrappers created for those objects.

[jbroman, 2017/04/28 19:07:03]

nit: "between" isn't clear about the direction (the other direction is of course
the wrapped value field). Maybe something along the lines of "Maps from C++
objects to their corresponding JavaScript wrappers. See also DOMDataStore."

[adithyas, 2017/04/28 20:19:43]

Oh right! This made sense in my head .. fixed.

 template <class KeyType>
 class DOMWrapperMap {
   USING_FAST_MALLOC(DOMWrapperMap);
 
  public:
   explicit DOMWrapperMap(v8::Isolate* isolate)
       : isolate_(isolate), map_(isolate) {}
 
   v8::Local<v8::Object> NewLocal(v8::Isolate* isolate, KeyType* key) {
     return map_.Get(key);
@@ skipping 107 matching lines @@
     static void DisposeWeak(const v8::WeakCallbackInfo<WeakCallbackDataType>&);
   };
 
   v8::Isolate* isolate_;
   typename PersistentValueMapTraits::MapType map_;
 };
 
 }  // namespace blink
 
 #endif  // DOMWrapperMap_h