Allow startup with missing V8 snapshot file.

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 "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "gin/gin_export.h"
@@ skipping 22 matching lines @@
     kSingleThread,
     kUseLocker
   };
 
   IsolateHolder();
   explicit IsolateHolder(AccessMode access_mode);
   ~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 snapshot should be loaded (by calling
+  // 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.
   static void Initialize(ScriptMode mode,
                          v8::ArrayBuffer::Allocator* allocator);
 
   v8::Isolate* isolate() { return isolate_; }
 
   // The implementations of Object.observe() and Promise enqueue v8 Microtasks
   // that should be executed just before control is returned to the message
   // loop. This method adds a MessageLoop TaskObserver which runs any pending
@@ skipping 15 matching lines @@
   scoped_ptr<RunMicrotasksObserver> task_observer_;
   scoped_ptr<V8IsolateMemoryDumpProvider> isolate_memory_dump_provider_;
   AccessMode access_mode_;
 
   DISALLOW_COPY_AND_ASSIGN(IsolateHolder);
 };
 
 }  // namespace gin
 
 #endif  // GIN_PUBLIC_ISOLATE_HOLDER_H_