[Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/bindings/modules/v8/BUILD.gn

 # Copyright 2014 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.
 
 import("//third_party/WebKit/Source/bindings/modules/v8/generated.gni")
 import("//third_party/WebKit/Source/bindings/scripts/scripts.gni")
 import("//third_party/WebKit/Source/modules/modules.gni")
 import("//third_party/WebKit/Source/modules/modules_idl_files.gni")
 
 visibility = [ "//third_party/WebKit/*" ]
 
 group("bindings_modules_v8_generated") {
   public_deps = [
     ":bindings_modules_impl_generated",
     ":bindings_modules_v8_generated_init_partial",
     ":generate_bindings_modules_v8_interfaces",
     ":generate_bindings_modules_v8_partial_interfaces",
     ":generate_bindings_modules_v8_partial_interfaces_for_testing",
+    ":generate_v8_snapshot_external_references",
   ]
 }
 
 idl_compiler("generate_bindings_modules_v8_interfaces") {
   sources = modules_definition_idl_files
   output_dir = bindings_modules_v8_output_dir
   output_name_suffix = ""
   target_component = "modules"
 }
 
@@ skipping 59 matching lines @@
     ":bindings_modules_v8_generated",
   ]
 
   if (!is_component_build && is_win) {
     # This target as a static library (for non-component builds) is >4GB on
     # Windows, this causes linking to fail. As a workaround, split it into
     # multiple shards.
     split_count = 5
   }
 }
+
+action("generate_v8_snapshot_external_references") {
+  script = "$bindings_scripts_dir/generate_v8_snapshot_external_references.py"
+  idl_files = core_idl_files + core_idl_with_modules_dependency_files +
+              modules_definition_idl_files
+  output = bindings_generated_v8_snapshot_external_references_file
+
+  inputs = idl_files + [ script ]
+  outputs = [
+    output,
+  ]
+
+  response_file_contents = rebase_path(idl_files, root_build_dir)
+  args = [
+    "--cache-dir",
+    rebase_path(bindings_scripts_output_dir, root_build_dir),
+    "--output",
+    rebase_path(output, root_build_dir),
+    "--idl-files-list",
+    "{{response_file_name}}",
+    "--info-dir",
+    rebase_path("$bindings_output_dir", root_build_dir),
+    "--target-component",
+    "modules",
+  ]
+
+  deps = [
+    "//third_party/WebKit/Source/bindings/core:interfaces_info_individual_core",
+    "//third_party/WebKit/Source/bindings/modules:interfaces_info",
+    "//third_party/WebKit/Source/bindings/modules:interfaces_info_individual_modules",
+    "//third_party/WebKit/Source/bindings/scripts:cached_jinja_templates",
+    "//third_party/WebKit/Source/bindings/scripts:cached_lex_yacc_tables",
+  ]
+}