[Bindings] Create and use V8 context snapshots

gin/public/isolate_holder.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GIN_PUBLIC_ISOLATE_HOLDER_H_
 #define GIN_PUBLIC_ISOLATE_HOLDER_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 41 matching lines @@
     kStableV8Extras,
     kStableAndExperimentalV8Extras,
   };
 
   explicit IsolateHolder(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner);
   IsolateHolder(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
                 AccessMode access_mode);
   IsolateHolder(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
                 AccessMode access_mode,
-                AllowAtomicsWaitMode atomics_wait_mode);
+                AllowAtomicsWaitMode atomics_wait_mode,
+                intptr_t* reference_table,
+                v8::StartupData* startup_data);
+  // To take snapshot of v8 Context.

[Yuki, 2017/05/30 14:35:56]

Let's be a little more descriptive.

// Creates an IsolateHolder from an existing v8::Isolate.
// v8::SnapshotCreator creates a new v8::Isolate, and we need to instantiate an
IsolateHolder from that v8::Isolate.

[peria, 2017/06/01 08:33:32]

Done.

+  explicit IsolateHolder(v8::Isolate* isolate);
   ~IsolateHolder();
 
   // Should be invoked once before creating IsolateHolder instances to
   // initialize V8 and Gin. In case V8_USE_EXTERNAL_STARTUP_DATA is
   // defined, V8's initial natives should be loaded (by calling
   // V8Initializer::LoadV8NativesFromFD or
   // V8Initializer::LoadV8Natives) before calling this method.  If the
   // snapshot file is available, it should also be loaded (by calling
   // V8Initializer::LoadV8SnapshotFromFD or
   // V8Initializer::LoadV8Snapshot) before calling this method.
@@ skipping 33 matching lines @@
   std::unique_ptr<RunMicrotasksObserver> task_observer_;
   std::unique_ptr<V8IsolateMemoryDumpProvider> isolate_memory_dump_provider_;
   AccessMode access_mode_;
 
   DISALLOW_COPY_AND_ASSIGN(IsolateHolder);
 };
 
 }  // namespace gin
 
 #endif  // GIN_PUBLIC_ISOLATE_HOLDER_H_