[AppRemoting] Break out AppRemoting shared module (re-land).

remoting/webapp/files.gni

Index: remoting/webapp/files.gni
diff --git a/remoting/webapp/files.gni b/remoting/webapp/files.gni
index 7e77289ddb4c443100a59809559504fe6b3653f0..2b4e66b0740937b2f87e0d4b97e295f9c87b6abc 100644
--- a/remoting/webapp/files.gni
+++ b/remoting/webapp/files.gni
@@ -164,7 +164,6 @@ remoting_webapp_shared_js_client_files = [
 
 # Remoting core JavaScript files.
 remoting_webapp_shared_js_core_files = [
-  "base/js/app_capabilities.js",
   "base/js/application.js",
   "base/js/base.js",
   "base/js/ipc.js",
@@ -539,7 +538,6 @@ ar_main_js_files = [
                      "app_remoting/js/app_remoting.js",
                      "app_remoting/js/app_remoting_activity.js",
                      "app_remoting/js/ar_auth_dialog.js",
-                     "app_remoting/js/ar_main.js",
                      "app_remoting/js/context_menu_adapter.js",
                      "app_remoting/js/context_menu_chrome.js",
                      "app_remoting/js/context_menu_dom.js",
@@ -551,8 +549,6 @@ ar_main_js_files = [
                      "app_remoting/js/loading_window.js",
                      "app_remoting/js/submenu_manager.js",
                      "app_remoting/js/window_activation_menu.js",
-                     "base/js/application.js",
-                     "base/js/base.js",
                      "base/js/message_window_helper.js",
                      "base/js/message_window_manager.js",
                    ] + remoting_webapp_shared_js_auth_google_files +
@@ -596,19 +592,33 @@ ar_feedback_consent_html_all_js_files = [
 ar_loading_window_template = "app_remoting/html/template_loading_window.html"
 
 #
-# AppRemoting background JS files.
-# These files are referenced from the manifest
+# AppRemoting ar_background.html generation files.
 #
 
-ar_background_js_files = [
+ar_background_template = "app_remoting/html/template_background.html"
+ar_background_html_js_files = [
   "app_remoting/js/ar_background.js",
   "base/js/platform.js",
 ]
 
+#
+# Vendor supplied files.
+# These need a full path specification because they are referenced from the
+# webapp directory (ar_sample_app) and from the internal app directory.
+#
+
+ar_vendor_js_files = [ "//remoting/webapp/app_remoting/vendor/arv_main.js" ]
+
+ar_vendor_html_files = [
+  "//remoting/webapp/app_remoting/vendor/arv_background.html",
+  "//remoting/webapp/app_remoting/vendor/arv_main.html",
+  "//remoting/webapp/app_remoting/vendor/arv_wcs_sandbox.html",
+]
+
 ar_all_js_files =
     ar_main_js_files + ar_feedback_consent_html_js_files +
     remoting_webapp_message_window_html_js_files +
-    remoting_webapp_wcs_sandbox_html_js_files + ar_background_js_files
+    remoting_webapp_wcs_sandbox_html_js_files + ar_background_html_js_files
 
 # Files that contain localizable strings.
 app_remoting_webapp_localizable_files =