[Closure GN] Convert simple WebUI Closure Compilation to GN.

See go/closure-compile-gn for details.

This CL converts the Closure Compilation from GYP to GN for the following:
- cryptotoken
- download_internals
- md_downloads
- md_extensions
- md_history
- md_user_manager
- offline_pages
- signin
- webapks
- welcome

A local closure compile can be run by setting closure_compile = true in
args.gn, and then running ninja -C out/Default webui_closure_compile.
Individual projects can be compiled via, for example,
ninja -C out/Default chrome/browser/resources/md_extensions:closure_compile

Bug: 632206
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I401fc54ee6c5202bd27855ba28d886677e52210e
Reviewed-on: https://chromium-review.googlesource.com/954772
Commit-Queue: calamity <calamity@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550956}

chrome/browser/resources/BUILD.gn

@@ -10,8 +10,17 @@ assert(!is_ios, "Chromium/iOS shouldn't use anything in //chrome")
 if (closure_compile) {
   group("closure_compile") {
     deps = [
+      "cryptotoken:closure_compile",
       "engagement:closure_compile",
       "md_bookmarks:closure_compile",
+      "md_downloads:closure_compile",
+      "md_extensions:closure_compile",
+      "md_history:closure_compile",
+      "md_user_manager:closure_compile",
+      "offline_pages:closure_compile",
+      "signin/dice_sync_confirmation:closure_compile",
+      "webapks:closure_compile",
+      "welcome/dice_welcome:closure_compile",
     ]
   }
 }

chrome/browser/resources/cryptotoken/BUILD.gn

@@ -0,0 +1,50 @@
+# Copyright 2018 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/closure_compiler/compile_js.gni")
+
+js_type_check("closure_compile") {
+  deps = [
+    ":approvedorigins",
+    ":b64",
+    ":closeable",
+    ":countdown",
+    ":errorcodes",
+    ":inherits",
+    ":origincheck",
+    ":sha256",
+    ":textfetcher",
+    ":timer",
+  ]
+}
+
+js_library("errorcodes") {
+}
+
+js_library("b64") {
+}
+
+js_library("approvedorigins") {
+}
+
+js_library("closeable") {
+}
+
+js_library("countdown") {
+}
+
+js_library("inherits") {
+}
+
+js_library("origincheck") {
+}
+
+js_library("sha256") {
+}
+
+js_library("textfetcher") {
+}
+
+js_library("timer") {
+}

chrome/browser/resources/download_internals/BUILD.gn

@@ -0,0 +1,36 @@
+# Copyright 2018 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/closure_compiler/compile_js.gni")
+
+js_type_check("closure_compile") {
+  deps = [
+    ":download_internals",
+    ":download_internals_browser_proxy",
+    ":download_internals_visuals",
+  ]
+}
+
+js_library("download_internals") {
+  deps = [
+    ":download_internals_browser_proxy",
+    "//ui/webui/resources/js:assert",
+    "//ui/webui/resources/js:cr",
+    "//ui/webui/resources/js:load_time_data",
+    "//ui/webui/resources/js:util",
+  ]
+}
+
+js_library("download_internals_browser_proxy") {
+  deps = [
+    "//ui/webui/resources/js:cr",
+  ]
+}
+
+js_library("download_internals_visuals") {
+  deps = [
+    ":download_internals_browser_proxy",
+    "//ui/webui/resources/js:cr",
+  ]
+}

chrome/browser/resources/md_downloads/BUILD.gn

@@ -1,3 +1,8 @@
+# Copyright 2018 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/closure_compiler/compile_js.gni")
 import("../optimize_webui.gni")
 
 optimize_webui("build") {
@@ -9,3 +14,87 @@ optimize_webui("build") {
   insert_in_head = "<base href=chrome://downloads>"
   js_out_files = [ "crisper.js" ]
 }
+
+js_type_check("closure_compile") {
+  deps = [
+    ":browser_proxy",
+    ":constants",
+    ":downloads",
+    ":externs",
+    ":item",
+    ":manager",
+    ":search_service",
+    ":toolbar",
+  ]
+}
+
+js_library("browser_proxy") {
+  deps = [
+    "//ui/webui/resources/js:cr",
+  ]
+}
+
+js_library("constants") {
+  deps = [
+    "//ui/webui/resources/js:cr",
+  ]
+}
+
+js_library("downloads") {
+  deps = [
+    ":manager",
+    "//ui/webui/resources/js:cr",
+  ]
+}
+
+js_library("externs") {
+}
+
+js_library("item") {
+  deps = [
+    ":browser_proxy",
+    ":constants",
+    ":externs",
+    "//third_party/polymer/v1_0/components-chromium/paper-behaviors:paper-inky-focus-behavior-extracted",
+    "//ui/webui/resources/js:cr",
+    "//ui/webui/resources/js:load_time_data",
+    "//ui/webui/resources/js:util",
+  ]
+}
+
+js_library("manager") {
+  deps = [
+    ":browser_proxy",
+    ":externs",
+    ":item",
+    ":search_service",
+    ":toolbar",
+    "//third_party/polymer/v1_0/components-chromium/iron-list:iron-list-extracted",
+    "//ui/webui/resources/js:cr",
+    "//ui/webui/resources/js:load_time_data",
+    "//ui/webui/resources/js:util",
+    "//ui/webui/resources/js/cr:ui",
+    "//ui/webui/resources/js/cr/ui:command",
+  ]
+  externs_list = [ "$externs_path/chrome_send.js" ]
+}
+
+js_library("search_service") {
+  deps = [
+    ":browser_proxy",
+    "//ui/webui/resources/js:cr",
+    "//ui/webui/resources/js:load_time_data",
+  ]
+}
+
+js_library("toolbar") {
+  deps = [
+    ":browser_proxy",
+    ":search_service",
+    "//third_party/polymer/v1_0/components-chromium/iron-a11y-announcer:iron-a11y-announcer-extracted",
+    "//ui/webui/resources/cr_elements/cr_action_menu:cr_action_menu",
+    "//ui/webui/resources/cr_elements/cr_toolbar:cr_toolbar",
+    "//ui/webui/resources/js:cr",
+    "//ui/webui/resources/js:util",
+  ]
+}