[Bindings] Create and use V8 context snapshots

gin/public/isolate_holder.h

Index: gin/public/isolate_holder.h
diff --git a/gin/public/isolate_holder.h b/gin/public/isolate_holder.h
index 0d9cb3b39ef17561c090cf57d0f8dc916a67f0c7..37d0fe77bcce8bc5e793602383738ac1485d3340 100644
--- a/gin/public/isolate_holder.h
+++ b/gin/public/isolate_holder.h
@@ -59,7 +59,11 @@ class GIN_EXPORT IsolateHolder {
                 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