Infrastructure for reading V8's initial snapshot from external files

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 29cc2083334b356d9caff02a5b75abc9bc562b49..1a091568dc675d4caab52ccef717196cfb0d0254 100644
--- a/gin/public/isolate_holder.h
+++ b/gin/public/isolate_holder.h
@@ -10,6 +10,10 @@
 #include "gin/gin_export.h"
 #include "v8/include/v8.h"
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#include "base/files/memory_mapped_file.h"
+#endif
+
 namespace gin {
 
 class PerIsolateData;
@@ -49,11 +53,26 @@ class GIN_EXPORT IsolateHolder {
   // thread.
   void RemoveRunMicrotasksObserver();
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+#ifdef OS_ANDROID
+  static bool LoadV8SnapshotFD(int natives_fd, int snapshot_fd);
+#endif
+  static bool LoadV8Snapshot();
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
  private:
   v8::Isolate* isolate_;
   scoped_ptr<PerIsolateData> isolate_data_;
   scoped_ptr<RunMicrotasksObserver> task_observer_;
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
+
+  static bool MapV8Files(
+    base::FilePath* natives_path, base::FilePath* snapshot_path,
+    int natives = -1, int snapshot = -1);
+
+#endif // V8_USE_EXTERNAL_STARTUP_DATA
+
   DISALLOW_COPY_AND_ASSIGN(IsolateHolder);
 };