Update from https://crrev.com/318214

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 34 matching lines @@
   // Microtasks each time a Task is completed. This method should be called
   // once, when a MessageLoop is created and it should be called on the
   // MessageLoop's thread.
   void AddRunMicrotasksObserver();
 
   // This method should also only be called once, and on the MessageLoop's
   // thread.
   void RemoveRunMicrotasksObserver();
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+  static const int kV8SnapshotBasePathKey;
   static const char kNativesFileName[];
   static const char kSnapshotFileName[];
 
   static bool LoadV8SnapshotFd(int natives_fd,
                                int64 natives_offset,
                                int64 natives_size,
                                int snapshot_fd,
                                int64 snapshot_offset,
                                int64 snapshot_size);
   static bool LoadV8Snapshot();
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
   static void GetV8ExternalSnapshotData(const char** natives_data_out,
                                         int* natives_size_out,
                                         const char** snapshot_data_out,
                                         int* snapshot_size_out);
 
  private:
   v8::Isolate* isolate_;
   scoped_ptr<PerIsolateData> isolate_data_;
   scoped_ptr<RunMicrotasksObserver> task_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(IsolateHolder);
 };
 
 }  // namespace gin
 
 #endif  // GIN_PUBLIC_ISOLATE_HOLDER_H_