CrOS Settings: Add skeleton page for multidevice section.

chrome/browser/resources/settings/basic_page/basic_page.js

 // Copyright 2015 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.
 
 /**
  * @fileoverview
  * 'settings-basic-page' is the settings page containing the actual settings.
  */
 Polymer({
   is: 'settings-basic-page',
 
   behaviors: [MainPageBehavior, WebUIListenerBehavior],
 
   properties: {
     /** Preferences state. */
     prefs: {
       type: Object,
       notify: true,
     },
 
     showAndroidApps: Boolean,

[dpapad, 2017/07/06 01:26:50]

Should lines 21-25 be wrapped in an <if expr="chromeos">...</if> ?

[Oren Blasberg, 2017/07/06 18:17:58]

Done. Btw, how does that work, if it's commented out and it's an "html" style
tag? I am guessing there is some nifty preprocessor which magically compiles
this out on non-CrOS platforms?

[dpapad, 2017/07/06 18:59:02]

Yes. GRIT is preprocessing those, see
https://cs.chromium.org/chromium/src/tools/grit/grit/format/html_inline_unitt....

The reason we put those "<if expr>" statements behind a comment is so that the
JS file still holds valid JS syntax, and therefore we can use still other tools
without them blowing up (like ESLint), and without having to preprocess the file
with GRIT first.

 
+    showMultidevice: Boolean,
+
     havePlayStoreApp: Boolean,
 
     /** @type {!AndroidAppsInfo|undefined} */
     androidAppsInfo: Object,
 
     showChromeCleanup: {
       type: Boolean,
       value: function() {
         return loadTimeData.valueExists('chromeCleanupEnabled') &&
             loadTimeData.getBoolean('chromeCleanupEnabled');
@@ skipping 143 matching lines @@
 
   // <if expr="chromeos">
   /**
    * @return {boolean}
    * @private
    */
   computeShowSecondaryUserBanner_: function() {
     return !this.hasExpandedSection_ &&
         loadTimeData.getBoolean('isSecondaryUser');
   },
+
+  /**
+   * Whether to show the multidevice settings page.
+   * @param {boolean|undefined} visibility
+   * @return {boolean}

[dpapad, 2017/07/06 01:26:50]

Nit: Move comment from line 190 to here, as
@return {boolean} Whether to show the multidevice settings page.

[Oren Blasberg, 2017/07/06 18:17:58]

Done.

+   * @private
+   */
+  showMultidevicePage_: function(visibility) {

[dpapad, 2017/07/06 01:26:50]

Where is this used?

[Oren Blasberg, 2017/07/06 18:17:58]

Oops. It was superseded by shouldShowMultidevice_ below. Removing this. Thanks!

+    return loadTimeData.getBoolean('enableMultideviceSettings') &&
+        this.showPage_(visibility);
+  },
   // </if>
 
   /** @private */
   onResetProfileBannerClosed_: function() {
     this.showResetProfileBanner_ = false;
   },
 
   /**
    * @param {!AndroidAppsInfo} info
    * @private
@@ skipping 17 matching lines @@
     // settings app is not yet available.
     if (!this.havePlayStoreApp &&
         (!this.androidAppsInfo || !this.androidAppsInfo.settingsAppAvailable)) {
       return false;
     }
 
     return true;
   },
 
   /**
+   * @return {boolean}
+   * @private
+   */
+  shouldShowMultidevice_: function() {
+    var visibility = /** @type {boolean|undefined} */ (
+        this.get('pageVisibility.multidevice'));
+    return this.showMultidevice && this.showPage_(visibility);
+  },
+
+  /**
    * Hides everything but the newly expanded subpage.
    * @private
    */
   onSubpageExpanded_: function() {
     this.hasExpandedSection_ = true;
   },
 
   /**
    * Render the advanced page now (don't wait for idle).
    * @private
@@ skipping 54 matching lines @@
 
   /**
    * @param {boolean} opened Whether the menu is expanded.
    * @return {string} Icon name.
    * @private
    */
   getArrowIcon_: function(opened) {
     return opened ? 'cr:arrow-drop-up' : 'cr:arrow-drop-down';
   },
 });