[serializer] include global proxy in additional context snapshots.

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 7542 matching lines @@
                   StartupData* existing_blob = nullptr);
 
   ~SnapshotCreator();
 
   /**
    * \returns the isolate prepared by the snapshot creator.
    */
   Isolate* GetIsolate();
 
   /**
-   * Add a context to be included in the snapshot blob.
+   * Set the default context to be included in the snapshot blob.
+   * The snapshot will not contain the global proxy, and we expect one or a
+   * global object template to create one, to be provided upon deserialization.
+   */
+  void SetDefaultContext(Local<Context> context);
+
+  /**
+   * Add additional context to be included in the snapshot blob.
+   * The snapshot will include the global proxy.
+   *
    * \returns the index of the context in the snapshot blob.
    */
   size_t AddContext(Local<Context> context);
 
   /**
    * Add a template to be included in the snapshot blob.
    * \returns the index of the template in the snapshot blob.
    */
   size_t AddTemplate(Local<Template> template_obj);
 
@@ skipping 303 matching lines @@
    * the newly created context. This global object must have been
    * created by a previous call to Context::New with the same global
    * template. The state of the global object will be completely reset
    * and only object identify will remain.
    */
   static Local<Context> New(
       Isolate* isolate, ExtensionConfiguration* extensions = NULL,
       MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
       MaybeLocal<Value> global_object = MaybeLocal<Value>());
 
-  static MaybeLocal<Context> FromSnapshot(
-      Isolate* isolate, size_t context_snapshot_index,
-      ExtensionConfiguration* extensions = nullptr,
-      MaybeLocal<ObjectTemplate> global_template = MaybeLocal<ObjectTemplate>(),
-      MaybeLocal<Value> global_object = MaybeLocal<Value>());
-
   /**
+   * Create a new context from a (non-default) context snapshot. There
+   * is no way to provide a global template or global proxy since the
+   * context snapshot already contains a global proxy.
+   *
+   * \param isolate See v8::Context::New.
+   *
+   * \param context_snapshot_index The index of the context snapshot to
+   * deserialize from. It must be larger than 0. Use v8::Context::New for the

[peria, 2016/12/07 10:11:08]

According to tests, we can use 0 for this index, right?

[Yang, 2016/12/07 10:13:34]

Nice catch. The comment is outdated. Fixed.

+   * default (0-th) snapshot.
+   *
+   * \param extensions See v8::Context::New.
+   */
+
+  static MaybeLocal<Context> FromSnapshot(
+      Isolate* isolate, size_t context_snapshot_index,
+      ExtensionConfiguration* extensions = nullptr);
+
+  /**
    * Returns an global object that isn't backed by an actual context.
    *
    * The global template needs to have access checks with handlers installed.
    * If an existing global object is passed in, the global object is detached
    * from its context.
    *
    * Note that this is different from a detached context where all accesses to
    * the global proxy will fail. Instead, the access check handlers are invoked.
    *
    * It is also not possible to detach an object returned by this method.
@@ skipping 1743 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_