Refactor ScriptData class for cached compile data.

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 1069 matching lines @@
     CachedData* cached_data;
   };
 
   enum CompileOptions {
     kNoCompileOptions,
     kProduceDataToCache = 1 << 0
   };
 
   /**
    * Compiles the specified script (context-independent).
+   * Cached data as part of the source object can be optionally produced to be
+   * consumed later to speed up compilation of identical source scripts.
+   *
+   * Note that when producing cached data, the source must point to NULL for
+   * cached data. When consuming cached data, the cached data must have been
+   * produced by the same version of V8.
    *
    * \param source Script source code.
    * \return Compiled script object (context independent; for running it must be
    *   bound to a context).
    */
   static Local<UnboundScript> CompileUnbound(
       Isolate* isolate, Source* source,
       CompileOptions options = kNoCompileOptions);
 
   /**
@@ skipping 5640 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_