[Bindings] Create and use V8 context snapshots

gin/v8_initializer.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_V8_INITIALIZER_H_
 #define GIN_V8_INITIALIZER_H_
 
 #include <stdint.h>
 
 #include "base/files/file.h"
@@ skipping 58 matching lines @@
 #if defined(OS_ANDROID)
   static base::PlatformFile GetOpenSnapshotFileForChildProcesses(
       base::MemoryMappedFile::Region* region_out,
       bool abi_32_bit);
 
   static base::FilePath GetNativesFilePath();
   static base::FilePath GetSnapshotFilePath(bool abi_32_bit);
 #endif
 
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
+  // Load V8 context snapshot from user provided platform file descriptors.
+  // Other details are same with LoadV8SnapshotFromFD.
+  static void LoadV8ContextSnapshotFromFD(base::PlatformFile snapshot_fd,
+                                          int64_t snapshot_offset,
+                                          int64_t snapshot_size);
+
+  // Load V8 context snapshot from default resources, if they are available.
+  static void LoadV8ContextSnapshot();
+
+  // Get address and size information for currently loaded V8 context snapshot.
+  // If no snapshot is loaded, the return values are nullptr and 0.
+  static void GetV8ContextSnapshotData(const char** snapshot_data_out,
+                                       int* snapshot_size_out);
 };
 
 }  // namespace gin
 
 #endif  // GIN_V8_INITIALIZER_H_