Add d8 functionality for switching between realms (a.k.a. contexts)

src/objects.h

 // Copyright 2012 the V8 project authors. 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 8519 matching lines @@
   static const int kNextOffset = kTableOffset + kPointerSize;
   static const int kSize = kNextOffset + kPointerSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap);
 };
 
 
 class JSArrayBuffer: public JSObject {
  public:
-  // [backing_store]: backing memory for thsi array
+  // [backing_store]: backing memory for this array
   DECL_ACCESSORS(backing_store, void)
 
   // [byte_length]: length in bytes
   DECL_ACCESSORS(byte_length, Object)
 
   // Casting.
   static inline JSArrayBuffer* cast(Object* obj);
 
   // Dispatched behavior.
   DECLARE_PRINTER(JSArrayBuffer)
@@ skipping 805 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_