[Bindings] Create and use V8 context snapshots

gin/v8_initializer.h

Index: gin/v8_initializer.h
diff --git a/gin/v8_initializer.h b/gin/v8_initializer.h
index 7d16c3eb6d940e39d2ba9ad5b1f4ba22eddb753a..4a3f9aaaba4eb0c8f7a913072e2e8c782e83a5ef 100644
--- a/gin/v8_initializer.h
+++ b/gin/v8_initializer.h
@@ -30,6 +30,8 @@ class GIN_EXPORT V8Initializer {
                                         int* natives_size_out,
                                         const char** snapshot_data_out,
                                         int* snapshot_size_out);
+  static void GetV8ContextData(const char** snapshot_data_out,
+                               int* snapshot_size_out);
 
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
 
@@ -76,6 +78,16 @@ class GIN_EXPORT V8Initializer {
 #endif
 
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
+  static void LoadV8ContextFromFD(base::PlatformFile snapshot_fd,
+                                  int64_t snapshot_offset,
+                                  int64_t snapshot_size);
+  static void LoadV8Context();
+  static base::PlatformFile GetOpenV8ContextFileForChildProcesses(
+      base::MemoryMappedFile::Region* region_out);
+#if defined(OS_ANDROID)
+  static base::FilePath GetV8ContextFilePath();
+#endif
 };
 
 }  // namespace gin