Migrate protocol/ to ESM

- InspectorBackendCommands is now loaded via ES Modules

Bug: 1006759
Change-Id: I2826518a55e1f4fd7704cfb04120885f9aa9b604
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1837772Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Tim Van der Lippe <tvanderlippe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702821}

third_party/blink/renderer/devtools/BUILD.gn

@@ -528,8 +528,6 @@ all_devtools_files = [
   "front_end/profiler/ProfileTypeRegistry.js",
   "front_end/profiler/ProfileView.js",
   "front_end/profiler/TopDownProfileDataGrid.js",
-  "front_end/protocol/NodeURL.js",
-  "front_end/protocol/InspectorBackend.js",
   "front_end/protocol/module.json",
   "front_end/quick_open/CommandMenu.js",
   "front_end/quick_open/filteredListWidget.css",
@@ -899,7 +897,9 @@ lighthouse_locale_files = [
 all_devtools_files += lighthouse_locale_files
 
 all_devtools_modules = [
-  "front_end/root.js",
+  "front_end/protocol/protocol.js",
+  "front_end/protocol/NodeURL.js",
+  "front_end/protocol/InspectorBackend.js",
   "front_end/host/host.js",
   "front_end/host/UserMetrics.js",
   "front_end/host/ResourceLoader.js",
@@ -1191,6 +1191,9 @@ application_templates = [
 ]
 
 copied_devtools_modules = [
+  "$resources_out_dir/protocol/protocol.js",
+  "$resources_out_dir/protocol/NodeURL.js",
+  "$resources_out_dir/protocol/InspectorBackend.js",
   "$resources_out_dir/host/host.js",
   "$resources_out_dir/host/UserMetrics.js",
   "$resources_out_dir/host/ResourceLoader.js",
@@ -1492,7 +1495,10 @@ action("generate_devtools_grd") {
   grd_files =
       copied_devtools_modules + generated_applications +
       generated_non_autostart_non_remote_modules + devtools_embedder_scripts +
-      [ "$resources_out_dir/devtools_extension_api.js" ]
+      [
+        "$resources_out_dir/devtools_extension_api.js",
+        "$resources_out_dir/InspectorBackendCommands.js",
+      ]
 
   # Bundle remote modules in ChromeOS.
   if (is_chromeos) {

third_party/blink/renderer/devtools/front_end/protocol/NodeURL.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-Protocol.NodeURL = class {
+export default class NodeURL {
   /**
    * @param {!Object} object
    */
@@ -14,7 +14,7 @@ Protocol.NodeURL = class {
      * @param {string} path
      */
     function process(object, path) {
-      if (object.url && Protocol.NodeURL._isPlatformPath(object.url, Host.isWin())) {
+      if (object.url && NodeURL._isPlatformPath(object.url, Host.isWin())) {
         object.url = Common.ParsedURL.platformPathToURL(object.url);
       }
       for (const entry of Object.entries(object)) {
@@ -41,4 +41,13 @@ Protocol.NodeURL = class {
       return fileSystemPath.length ? fileSystemPath[0] === '/' : false;
     }
   }
-};
+}
+
+/* Legacy exported object */
+self.Protocol = self.Protocol || {};
+
+/* Legacy exported object */
+Protocol = Protocol || {};
+
+/** @constructor */
+Protocol.NodeURL = NodeURL;

third_party/blink/renderer/devtools/front_end/protocol/module.json

@@ -3,7 +3,9 @@
     "common",
     "host"
   ],
-  "scripts": [
+  "scripts": [],
+  "modules": [
+    "protocol.js",
     "NodeURL.js",
     "InspectorBackend.js",
     "../InspectorBackendCommands.js"

third_party/blink/renderer/devtools/front_end/protocol/protocol.js

+// Copyright 2019 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 './InspectorBackend.js';
+import './NodeURL.js';
+import '../InspectorBackendCommands.js';
+
+import * as InspectorBackend from './InspectorBackend.js';
+import * as NodeURL from './NodeURL.js';
+
+export {
+  InspectorBackend,
+  NodeURL,
+};

third_party/blink/renderer/devtools/front_end/root.js

@@ -7,4 +7,5 @@ import './platform/utilities.js';
 import './dom_extension/DOMExtension.js';
 import './common/common.js';
 import './host/host.js';
+import './protocol/protocol.js';
 import './ui/ui.js';

third_party/blink/renderer/devtools/front_end/sdk_test_runner/PageMockTestRunner.js

@@ -48,13 +48,13 @@ SDKTestRunner.PageMock = class {
     this._enabledDomains.clear();
     SDK.targetManager._targets = [];
 
-    const oldFactory = Protocol.Connection._factory;
-    Protocol.Connection._factory = () => {
+    const oldFactory = Protocol.Connection.getFactory();
+    Protocol.Connection.setFactory(() => {
       this._connection = new MockPageConnection(this);
       return this._connection;
-    };
+    });
     const target = SDK.targetManager.createTarget(nextId('mock-target-'), targetName, this._type, null);
-    Protocol.Connection._factory = oldFactory;
+    Protocol.Connection.setFactory(oldFactory);
 
     this._target = target;
     return target;

third_party/blink/renderer/devtools/scripts/compile_frontend.py

@@ -290,6 +290,12 @@ def prepare_closure_frontend_compile(temp_devtools_path, descriptors, namespace_
         args.extend(['--js', file])
         if "InspectorBackend.js" in file:
             args.extend(['--js', protocol_externs_file])
+
+            # Write a dummy file for InspectorBackendCommands. We don't type-check this file, but we
+            # import it from protocol/protocol.js
+            inspector_backends_commands_file = path.join(temp_frontend_path, 'InspectorBackendCommands.js')
+            modular_build.write_file(inspector_backends_commands_file, '')
+            args.extend(['--js', inspector_backends_commands_file])
     command += args
     command = [arg.replace(DEVTOOLS_FRONTEND_PATH, temp_frontend_path) for arg in command]
     compiler_args_file = tempfile.NamedTemporaryFile(mode='wt', delete=False)