chrome://browser-switch: show error messages

Bug: 887005
Change-Id: Ic5940c15a652c0fceea34f8a1ca493b7707d9236
Reviewed-on: https://chromium-review.googlesource.com/c/1467022
Commit-Queue: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632013}

chrome/app/generated_resources.grd

@@ -4716,13 +4716,22 @@ Keep your key file in a safe place. You will need it to create new versions of y
         </message>
       </if>
 
-      <!-- about:browser-switch strings -->
+      <!-- chrome://browser-switch strings -->
       <if expr="is_win or is_macosx or (is_linux and not is_chromeos)">
         <message name="IDS_ABOUT_BROWSER_SWITCH_TITLE" desc="about:browser-switch page title">
           Legacy Browser Support
         </message>
-        <message name="IDS_ABOUT_BROWSER_SWITCH_OPENING" desc="Shown while waiting for an alternative browser to open">
-          Opening in alternate browser now.
+        <message name="IDS_ABOUT_BROWSER_SWITCH_OPENING_TITLE" desc="Shown while waiting for an alternative browser to open">
+          Opening in alternative browser now
+        </message>
+        <message name="IDS_ABOUT_BROWSER_SWITCH_ERROR_TITLE" desc="Error message shown when we fail to open the alternative browser">
+          The alternative browser could not be opened
+        </message>
+        <message name="IDS_ABOUT_BROWSER_SWITCH_GENERIC_ERROR" desc="Generic error message when we don't know why we failed to open the alternative browser">
+          <ph name="URL">$1<ex>ftp://example.com/</ex></ph> could not be open in an alternative browser. Please contact your system administrator.
+        </message>
+        <message name="IDS_ABOUT_BROWSER_SWITCH_PROTOCOL_ERROR" desc="Specific error message when we failed to open the alternative browser, because the URL is not one of http://, https:// or file://">
+          Only http, https and file protocols are supported for browser redirects.
         </message>
       </if>
 

chrome/browser/resources/browser_switcher/app.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 
 <link rel="import" href="chrome://resources/html/cr.html">
+<link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/cr_elements/shared_vars_css.html">
 <link rel="import" href="browser_switcher_proxy.html">
 
@@ -35,8 +36,8 @@
       }
     </style>
 
-    <h1>$i18n{opening}</h1>
-    <p>$i18n{description}</p>
+    <h1>[[computeTitle_(error_)]]</h1>
+    <p inner-h-t-m-l="[[computeDescription_(url_, error_)]]"></p>
   </template>
   <script src="app.js"></script>
 </dom-module>

chrome/browser/resources/browser_switcher/app.js

@@ -6,9 +6,17 @@
 
 (function() {
 
+/** @enum {string} */
+const LaunchError = {
+  GENERIC_ERROR: 'genericError',
+  PROTOCOL_ERROR: 'protocolError',
+};
+
 Polymer({
   is: 'browser-switcher-app',
 
+  behaviors: [I18nBehavior],
+
   properties: {
     /**
      * URL to launch in the alternative browser.
@@ -20,6 +28,15 @@ Polymer({
         return (new URLSearchParams(window.location.search)).get('url') || '';
       },
     },
+
+    /**
+     * Error message, or empty string if no error has occurred (yet).
+     * @private
+     */
+    error_: {
+      type: String,
+      value: '',
+    },
   },
 
   /** @override */
@@ -39,6 +56,7 @@ Polymer({
     const anchor = document.createElement('a');
     anchor.href = this.url_;
     if (!/^(file|http|https):$/.test(anchor.protocol)) {
+      this.error_ = LaunchError.PROTOCOL_ERROR;
       return;
     }
 
@@ -46,7 +64,38 @@ Polymer({
     // immediately re-trigger LBS.
     history.pushState({}, '', '/?done=true');
 
-    proxy.launchAlternativeBrowserAndCloseTab(this.url_);
+    proxy.launchAlternativeBrowserAndCloseTab(this.url_).catch(() => {
+      this.error_ = LaunchError.GENERIC_ERROR;
+    });
+  },
+
+  /**
+   * @return {string}
+   * @private
+   */
+  computeTitle_: function() {
+    if (this.error_) {
+      return this.i18n('errorTitle');
+    }
+    return this.i18n('openingTitle');
+  },
+
+  /**
+   * @return {string}
+   * @private
+   */
+  computeDescription_: function() {
+    if (this.error_) {
+      return this.i18n(this.error_, getUrlHostname(this.url_));
+    }
+    return this.i18n('description');
   },
 });
+
+function getUrlHostname(url) {
+  const anchor = document.createElement('a');
+  anchor.href = url;
+  // Return entire url if parsing failed (which means the URL is bogus).
+  return anchor.hostname || url;
+}
 })();

chrome/browser/resources/browser_switcher/browser_switcher.html

@@ -26,6 +26,8 @@
   <link rel="stylesheet" href="chrome://resources/css/md_colors.css">
   <link rel="stylesheet" href="chrome://resources/css/text_defaults_md.css">
 
+  <link rel="import" href="chrome://resources/html/load_time_data.html">
+  <script src="strings.js"></script>
   <link rel="import" href="app.html">
 </body>
 </html>

chrome/browser/ui/webui/browser_switcher/browser_switch_ui.cc

@@ -70,7 +70,14 @@ content::WebUIDataSource* CreateBrowserSwitchUIHTMLSource(
 
   source->AddLocalizedString("description",
                              IDS_ABOUT_BROWSER_SWITCH_DESCRIPTION);
-  source->AddLocalizedString("opening", IDS_ABOUT_BROWSER_SWITCH_OPENING);
+  source->AddLocalizedString("errorTitle",
+                             IDS_ABOUT_BROWSER_SWITCH_ERROR_TITLE);
+  source->AddLocalizedString("genericError",
+                             IDS_ABOUT_BROWSER_SWITCH_GENERIC_ERROR);
+  source->AddLocalizedString("openingTitle",
+                             IDS_ABOUT_BROWSER_SWITCH_OPENING_TITLE);
+  source->AddLocalizedString("protocolError",
+                             IDS_ABOUT_BROWSER_SWITCH_PROTOCOL_ERROR);
   source->AddLocalizedString("title", IDS_ABOUT_BROWSER_SWITCH_TITLE);
 
   source->AddResourcePath("app.html", IDR_BROWSER_SWITCHER_APP_HTML);
@@ -83,6 +90,7 @@ content::WebUIDataSource* CreateBrowserSwitchUIHTMLSource(
                           IDR_BROWSER_SWITCHER_BROWSER_SWITCHER_PROXY_JS);
 
   source->SetDefaultResource(IDR_BROWSER_SWITCHER_BROWSER_SWITCH_HTML);
+  source->SetJsonPath("strings.js");
   source->UseGzip();
 
   return source;