[Bindings] Create and use V8 context snapshots

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

Index: third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
diff --git a/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn b/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
index 82d9b97d2e6a11b48e22f0828c5097b5ce560bf7..a78723b0722e918899029a37643643dce290c48c 100644
--- a/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
+++ b/third_party/WebKit/Source/bindings/modules/v8/BUILD.gn
@@ -15,6 +15,7 @@ group("bindings_modules_generated") {
     ":bindings_modules_v8_generated_init_partial",
     ":generate_bindings_modules_v8_interfaces",
     ":generate_bindings_modules_v8_partial_interfaces",
+    ":generate_v8_snapshot_external_references",
   ]
 }
 
@@ -68,3 +69,37 @@ action("bindings_modules_v8_generated_init_partial") {
     "//third_party/WebKit/Source/bindings/modules:interfaces_info",
   ]
 }
+
+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",
+  ]
+}