[api] Add documentation for PropertyCallbackInfo.

include/v8.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 3218 matching lines @@
 };
 
 
 /**
  * The information passed to a property callback about the context
  * of the property access.
  */
 template<typename T>
 class PropertyCallbackInfo {
  public:
+  /**
+   * \return The isolate of the property access.
+   */
   V8_INLINE Isolate* GetIsolate() const;
+
+  /**
+   * \return The data set in the configuration, i.e., in
+   * `NamedPropertyHandlerConfiguration` or
+   * `IndexedPropertyHandlerConfiguration.`
+   */
   V8_INLINE Local<Value> Data() const;
+
   V8_INLINE Local<Object> This() const;
+
+  /**
+   * \return The object in the prototype chain of the receiver that has the
+   * interceptor. Suppose you have `x` and its prototype is `y`, and `y`
+   * has an interceptor. Then `info.This()` is `x` and `info.Holder()` is `y`.
+   * The Holder() could be a hidden object (the global object, rather
+   * than the global proxy).
+   *
+   * \note For security reasons, do not pass the object back into the runtime.
+   */
   V8_INLINE Local<Object> Holder() const;
+
+  /**
+   * \return The return value of the callback.
+   * Can be changed by calling Set().
+   * \code
+   * info.GetReturnValue().Set(...)
+   * \endcode
+   *
+   */
   V8_INLINE ReturnValue<T> GetReturnValue() const;
+
+  /**
+   * \return True if the intercepted function should throw if an error occurs.
+   * Usually, `true` corresponds to `'use strict'`.
+   *
+   * \note Always `false` when intercepting `Reflect.Set()`
+   * independent of the language mode.
+   */
   V8_INLINE bool ShouldThrowOnError() const;
+
   // This shouldn't be public, but the arm compiler needs it.
   static const int kArgsLength = 7;
 
  protected:
   friend class MacroAssembler;
   friend class internal::PropertyCallbackArguments;
   friend class internal::CustomArguments<PropertyCallbackInfo>;
   static const int kShouldThrowOnErrorIndex = 0;
   static const int kHolderIndex = 1;
   static const int kIsolateIndex = 2;
@@ skipping 5731 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_