--- a/browser/base/content/browser-readinglist.js
+++ b/browser/base/content/browser-readinglist.js
@@ -5,25 +5,44 @@
 */
 
 XPCOMUtils.defineLazyModuleGetter(this, "ReadingList",
   "resource:///modules/readinglist/ReadingList.jsm");
 
 const READINGLIST_COMMAND_ID = "readingListSidebar";
 
 let ReadingListUI = {
+  /**
+   * Frame-script messages we want to listen to.
+   * @type {[string]}
+   */
   MESSAGES: [
     "ReadingList:GetVisibility",
     "ReadingList:ToggleVisibility",
   ],
 
   /**
+   * Add-to-ReadingList toolbar button in the URLbar.
+   * @type {Element}
+   */
+  toolbarButton: null,
+
+  /**
+   * Whether this object is currently registered as a listener with ReadingList.
+   * Used to avoid inadvertantly loading the ReadLingList.jsm module on startup.
+   * @type {Boolean}
+   */
+  listenerRegistered: false,
+
+  /**
    * Initialize the ReadingList UI.
    */
   init() {
+    this.toolbarButton = document.getElementById("readinglist-addremove-button");
+
     Preferences.observe("browser.readinglist.enabled", this.updateUI, this);
 
     const mm = window.messageManager;
     for (let msg of this.MESSAGES) {
       mm.addMessageListener(msg, this);
     }
 
     this.updateUI();
@@ -58,17 +77,28 @@ let ReadingListUI = {
   },
 
   /**
    * Update the UI status, ensuring the UI is shown or hidden depending on
    * whether the feature is enabled or not.
    */
   updateUI() {
     let enabled = this.enabled;
-    if (!enabled) {
+    if (enabled) {
+      // This is a no-op if we're already registered.
+      ReadingList.addListener(this);
+      this.listenerRegistered = true;
+    } else {
+      if (this.listenerRegistered) {
+        // This is safe to call if we're not currently registered, but we don't
+        // want to forcibly load the normally lazy-loaded module on startup.
+        ReadingList.removeListener(this);
+        this.listenerRegistered = true;
+      }
+
       this.hideSidebar();
     }
 
     document.getElementById(READINGLIST_COMMAND_ID).setAttribute("hidden", !enabled);
   },
 
   /**
    * Show the ReadingList sidebar.
@@ -84,16 +114,21 @@ let ReadingListUI = {
    * Hide the ReadingList sidebar, if it is currently shown.
    */
   hideSidebar() {
     if (this.isSidebarOpen) {
       SidebarUI.hide();
     }
   },
 
+  /**
+   * Re-refresh the ReadingList bookmarks submenu when it opens.
+   *
+   * @param {Element} target - Menu element opening.
+   */
   onReadingListPopupShowing: Task.async(function* (target) {
     if (target.id == "BMB_readingListPopup") {
       // Setting this class in the .xul file messes with the way
       // browser-places.js inserts bookmarks in the menu.
       document.getElementById("BMB_viewReadingListSidebar")
               .classList.add("panel-subview-footer");
     }
 
@@ -179,9 +214,101 @@ let ReadingListUI = {
       }
 
       case "ReadingList:ToggleVisibility": {
         this.toggleSidebar();
         break;
       }
     }
   },
+
+  /**
+   * Handles toolbar button styling based on page proxy state changes.
+   *
+   * @see SetPageProxyState()
+   *
+   * @param {string} state - New state. Either "valid" or "invalid".
+   */
+  onPageProxyStateChanged: Task.async(function* (state) {
+    if (!this.toolbarButton) {
+      // nothing to do if we have no button.
+      return;
+    }
+    if (!this.enabled || state == "invalid") {
+      this.toolbarButton.setAttribute("hidden", true);
+      return;
+    }
+
+    let isInList = yield ReadingList.containsURL(gBrowser.currentURI);
+    this.setToolbarButtonState(isInList);
+  }),
+
+  /**
+   * Set the state of the ReadingList toolbar button in the urlbar.
+   * If the current tab's page is in the ReadingList (active), sets the button
+   * to allow removing the page. Otherwise, sets the button to allow adding the
+   * page (not active).
+   *
+   * @param {boolean} active - True if the button should be active (page is
+   *                           already in the list).
+   */
+  setToolbarButtonState(active) {
+    this.toolbarButton.setAttribute("already-added", active);
+
+    let type = (active ? "remove" : "add");
+    let tooltip = gNavigatorBundle.getString(`readingList.urlbar.${type}`);
+    this.toolbarButton.setAttribute("tooltiptext", tooltip);
+
+    this.toolbarButton.removeAttribute("hidden");
+  },
+
+  /**
+   * Toggle a page (from a browser) in the ReadingList, adding if it's not already added, or
+   * removing otherwise.
+   *
+   * @param {<xul:browser>} browser - Browser with page to toggle.
+   * @returns {Promise} Promise resolved when operation has completed.
+   */
+  togglePageByBrowser: Task.async(function* (browser) {
+    let item = yield ReadingList.getItemForURL(browser.currentURI);
+    if (item) {
+      yield item.delete();
+    } else {
+      yield ReadingList.addItemFromBrowser(browser);
+    }
+  }),
+
+  /**
+   * Checks if a given item matches the current tab in this window.
+   *
+   * @param {ReadingListItem} item - Item to check
+   * @returns True if match, false otherwise.
+   */
+  isItemForCurrentBrowser(item) {
+    let currentURL = gBrowser.currentURI.spec;
+    if (item.url == currentURL || item.resolvedURL == currentURL) {
+      return true;
+    }
+    return false;
+  },
+
+  /**
+   * ReadingList event handler for when an item is added.
+   *
+   * @param {ReadingListItem} item - Item added.
+   */
+  onItemAdded(item) {
+    if (this.isItemForCurrentBrowser(item)) {
+      this.setToolbarButtonState(true);
+    }
+  },
+
+  /**
+   * ReadingList event handler for when an item is deleted.
+   *
+   * @param {ReadingListItem} item - Item deleted.
+   */
+  onItemDeleted(item) {
+    if (this.isItemForCurrentBrowser(item)) {
+      this.setToolbarButtonState(false);
+    }
+  },
 };

--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1017,16 +1017,17 @@ var gBrowserInit = {
       }
       goSetCommandEnabled("cmd_newNavigatorTab", false);
     }
 
     // Misc. inits.
     CombinedStopReload.init();
     gPrivateBrowsingUI.init();
     TabsInTitlebar.init();
+    ReadingListUI.init();
 
 #ifdef XP_WIN
     if (window.matchMedia("(-moz-os-version: windows-win8)").matches &&
         window.matchMedia("(-moz-windows-default-theme)").matches) {
       let windowFrameColor = Cu.import("resource:///modules/Windows8WindowFrameColor.jsm", {})
                                .Windows8WindowFrameColor.get();
 
       // Formula from W3C's WCAG 2.0 spec's color ratio and relative luminance,
@@ -1374,17 +1375,16 @@ var gBrowserInit = {
         return;
       }
 
       // Enable the Restore Last Session command if needed
       RestoreLastSessionObserver.init();
 
       SocialUI.init();
       TabView.init();
-      ReadingListUI.init();
 
       // Telemetry for master-password - we do this after 5 seconds as it
       // can cause IO if NSS/PSM has not already initialized.
       setTimeout(() => {
         if (window.closed) {
           return;
         }
         let secmodDB = Cc["@mozilla.org/security/pkcs11moduledb;1"]
@@ -2416,16 +2416,17 @@ function UpdatePageProxyState()
 {
   if (gURLBar && gURLBar.value != gLastValidURLStr)
     SetPageProxyState("invalid");
 }
 
 function SetPageProxyState(aState)
 {
   BookmarkingUI.onPageProxyStateChanged(aState);
+  ReadingListUI.onPageProxyStateChanged(aState);
 
   if (!gURLBar)
     return;
 
   if (!gProxyFavIcon)
     gProxyFavIcon = document.getElementById("page-proxy-favicon");
 
   gURLBar.setAttribute("pageproxystate", aState);

--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -822,16 +822,20 @@
                 <label class="urlbar-display urlbar-display-switchtab" value="&urlbar.switchToTab.label;"/>
               </box>
               <hbox id="urlbar-icons">
                 <image id="page-report-button"
                        class="urlbar-icon"
                        hidden="true"
                        tooltiptext="&pageReportIcon.tooltip;"
                        onclick="gPopupBlockerObserver.onReportButtonClick(event);"/>
+                <toolbarbutton id="readinglist-addremove-button"
+                               class="tabbable urlbar-icon"
+                               hidden="true"
+                               oncommand="ReadingListUI.togglePageByBrowser(gBrowser.selectedBrowser);"/>
                 <toolbarbutton id="reader-mode-button"
                                class="tabbable"
                                hidden="true"
                                onclick="ReaderParent.handleReaderButtonEvent(event);"
                                onkeypress="ReaderParent.handleReaderButtonEvent(event);"/>
               </hbox>
               <toolbarbutton id="urlbar-go-button"
                              class="chromeclass-toolbar-additional"

--- a/browser/base/content/content.js
+++ b/browser/base/content/content.js
@@ -1012,30 +1012,30 @@ addEventListener("pageshow", function(ev
   if (event.target == content.document) {
     sendAsyncMessage("PageVisibility:Show", {
       persisted: event.persisted,
     });
   }
 });
 
 let PageMetadataMessenger = {
-  init: function() {
+  init() {
     addMessageListener("PageMetadata:GetPageData", this);
     addMessageListener("PageMetadata:GetMicrodata", this);
   },
-  receiveMessage: function(aMessage) {
-    switch(aMessage.name) {
+  receiveMessage(message) {
+    switch(message.name) {
       case "PageMetadata:GetPageData": {
         let result = PageMetadata.getData(content.document);
         sendAsyncMessage("PageMetadata:PageDataResult", result);
         break;
       }
 
       case "PageMetadata:GetMicrodata": {
-        let target = aMessage.objects;
+        let target = message.objects;
         let result = PageMetadata.getMicrodata(content.document, target);
         sendAsyncMessage("PageMetadata:MicrodataResult", result);
         break;
       }
     }
   }
 }
 PageMetadataMessenger.init();

--- a/browser/components/readinglist/ReadingList.jsm
+++ b/browser/components/readinglist/ReadingList.jsm
@@ -125,16 +125,48 @@ ReadingListImpl.prototype = {
    * @return Promise<number> The number of matching items in the list.  Rejected
    *         with an Error on error.
    */
   count: Task.async(function* (...optsList) {
     return (yield this._store.count(...optsList));
   }),
 
   /**
+   * Checks whether a given URL is in the ReadingList already.
+   *
+   * @param {String/nsIURI} url - URL to check.
+   * @returns {Promise} Promise that is fulfilled with a boolean indicating
+   *                    whether the URL is in the list or not.
+   */
+  containsURL: Task.async(function* (url) {
+    url = normalizeURI(url).spec;
+
+    // This is used on every tab switch and page load of the current tab, so we
+    // want it to be quick and avoid a DB query whenever possible.
+
+    // First check if any cached items have a direct match.
+    if (this._itemsByURL.has(url)) {
+      return true;
+    }
+
+    // Then check if any cached items may have a different resolved URL
+    // that matches.
+    for (let itemWeakRef of this._itemsByURL.values()) {
+      let item = itemWeakRef.get();
+      if (item && item.resolvedURL == url) {
+        return true;
+      }
+    }
+
+    // Finally, fall back to the DB.
+    let count = yield this.count({url: url}, {resolvedURL: url});
+    return (count > 0);
+  }),
+
+  /**
    * Enumerates the items in the list that match the given options.
    *
    * @param callback Called for each item in the enumeration.  It's passed a
    *        single object, a ReadingListItem.  It may return a promise; if so,
    *        the callback will not be called for the next item until the promise
    *        is resolved.
    * @param optsList A variable number of options objects that control the
    *        items that are matched.  See Options Objects.
@@ -185,16 +217,17 @@ ReadingListImpl.prototype = {
    * returned promise is rejected in that case.
    *
    * @param obj A simple object representing an item.
    * @return Promise<ReadingListItem> Resolved with the new item when the list
    *         is updated.  Rejected with an Error on error.
    */
   addItem: Task.async(function* (obj) {
     obj = stripNonItemProperties(obj);
+    normalizeReadingListProperties(obj);
     yield this._store.addItem(obj);
     this._invalidateIterators();
     let item = this._itemFromObject(obj);
     this._callListeners("onItemAdded", item);
     let mm = Cc["@mozilla.org/globalmessagemanager;1"].getService(Ci.nsIMessageListenerManager);
     mm.broadcastAsyncMessage("Reader:Added", item);
     return item;
   }),
@@ -243,21 +276,48 @@ ReadingListImpl.prototype = {
 
   /**
    * Find any item that matches a given URL - either the item's URL, or its
    * resolved URL.
    *
    * @param {String/nsIURI} uri - URI to match against. This will be normalized.
    */
   getItemForURL: Task.async(function* (uri) {
-    let url = this._normalizeURI(uri).spec;
+    let url = normalizeURI(uri).spec;
     let [item] = yield this.iterator({url: url}, {resolvedURL: url}).items(1);
     return item;
   }),
 
+   /**
+   * Add to the ReadingList the page that is loaded in a given browser.
+   *
+   * @param {<xul:browser>} browser - Browser element for the document.
+   * @return {Promise} Promise that is fullfilled with the added item.
+   */
+  addItemFromBrowser: Task.async(function* (browser) {
+    let metadata = yield getMetadataFromBrowser(browser);
+    let itemData = {
+      url: browser.currentURI,
+      title: metadata.title,
+      resolvedURL: metadata.url,
+      excerpt: metadata.description,
+    };
+
+    if (metadata.description) {
+      itemData.exerpt = metadata.description;
+    }
+
+    if (metadata.previews.length > 0) {
+      itemData.image = metadata.previews[0];
+    }
+
+    let item = yield ReadingList.addItem(itemData);
+    return item;
+  }),
+
   /**
    * Adds a listener that will be notified when the list changes.  Listeners
    * are objects with the following optional methods:
    *
    *   onItemAdded(item)
    *   onItemUpdated(item)
    *   onItemDeleted(item)
    *
@@ -300,32 +360,16 @@ ReadingListImpl.prototype = {
   // A Set containing nsIWeakReferences that refer to valid iterators produced
   // by the list.
   _iterators: null,
 
   // A Set containing listener objects.
   _listeners: null,
 
   /**
-   * Normalize a URI, stripping away extraneous parts we don't want to store
-   * or compare against.
-   *
-   * @param {nsIURI/String} uri - URI to normalize.
-   * @returns {nsIURI} Cloned and normalized version of the input URI.
-   */
-  _normalizeURI(uri) {
-    if (typeof uri == "string") {
-      uri = Services.io.newURI(uri, "", null);
-    }
-    uri = uri.cloneIgnoringRef();
-    uri.userPass = "";
-    return uri;
-  },
-
-  /**
    * Returns the ReadingListItem represented by the given simple object.  If
    * the item doesn't exist yet, it's created first.
    *
    * @param obj A simple object with item properties.
    * @return The ReadingListItem.
    */
   _itemFromObject(obj) {
     let itemWeakRef = this._itemsByURL.get(obj.url);
@@ -370,22 +414,36 @@ ReadingListImpl.prototype = {
         catch (err) {
           Cu.reportError(err);
         }
       }
     }
   },
 
   _ensureItemBelongsToList(item) {
-    if (item.list != this) {
-      throw new Error("The item does not belong to this list");
+    if (!item || !item._ensureBelongsToList) {
+      throw new Error("The item is not a ReadingListItem");
     }
+    item._ensureBelongsToList();
   },
 };
 
+/*
+ * normalize the properties of a "regular" object that reflects a ReadingListItem
+ */
+function normalizeReadingListProperties(obj) {
+  if (obj.url) {
+    obj.url = normalizeURI(obj.url).spec;
+  }
+  if (obj.resolvedURL) {
+    obj.resolvedURL = normalizeURI(obj.resolvedURL).spec;
+  }
+}
+
+
 let _unserializable = () => {}; // See comments in the ReadingListItem ctor.
 
 /**
  * An item in a reading list.
  *
  * Each item belongs to a list, and it's an error to use an item with a
  * ReadingList that the item doesn't belong to.
  *
@@ -426,65 +484,53 @@ ReadingListItem.prototype = {
    * guarenteed to be set for local items.
    * @type string
    */
   get guid() {
     return this._properties.guid || undefined;
   },
   set guid(val) {
     this._properties.guid = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The date the item was last modified.
    * @type Date
    */
   get lastModified() {
     return this._properties.lastModified ?
            new Date(this._properties.lastModified) :
            undefined;
   },
   set lastModified(val) {
     this._properties.lastModified = val.valueOf();
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's URL.
    * @type string
    */
   get url() {
     return this._properties.url;
   },
   set url(val) {
-    this._properties.url = val;
-    if (this.list) {
-      this.commit();
-    }
+    this._properties.url = normalizeURI(val).spec;
   },
 
   /**
    * The item's URL as an nsIURI.
    * @type nsIURI
    */
   get uri() {
     return this._properties.url ?
            Services.io.newURI(this._properties.url, "", null) :
            undefined;
   },
   set uri(val) {
-    this.url = val.spec;
-    if (this.list) {
-      this.commit();
-    }
+    this.url = normalizeURI(val).spec;
   },
 
   /**
    * Returns the domain (a string) of the item's URL.  If the URL doesn't have a
    * domain, then the URL itself (also a string) is returned.
    */
   get domain() {
     try {
@@ -497,265 +543,211 @@ ReadingListItem.prototype = {
   /**
    * The item's resolved URL.
    * @type string
    */
   get resolvedURL() {
     return this._properties.resolvedURL;
   },
   set resolvedURL(val) {
-    this._properties.resolvedURL = val;
-    if (this.list) {
-      this.commit();
-    }
+    this._properties.resolvedURL = normalizeURI(val).spec;
   },
 
   /**
    * The item's resolved URL as an nsIURI.
    * @type nsIURI
    */
   get resolvedURI() {
     return this._properties.resolvedURL ?
            Services.io.newURI(this._properties.resolvedURL, "", null) :
            undefined;
   },
   set resolvedURI(val) {
     this.resolvedURL = val.spec;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's title.
    * @type string
    */
   get title() {
     return this._properties.title;
   },
   set title(val) {
     this._properties.title = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's resolved title.
    * @type string
    */
   get resolvedTitle() {
     return this._properties.resolvedTitle;
   },
   set resolvedTitle(val) {
     this._properties.resolvedTitle = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's excerpt.
    * @type string
    */
   get excerpt() {
     return this._properties.excerpt;
   },
   set excerpt(val) {
     this._properties.excerpt = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's status.
    * @type integer
    */
   get status() {
     return this._properties.status;
   },
   set status(val) {
     this._properties.status = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * Whether the item is a favorite.
    * @type boolean
    */
   get favorite() {
     return !!this._properties.favorite;
   },
   set favorite(val) {
     this._properties.favorite = !!val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * Whether the item is an article.
    * @type boolean
    */
   get isArticle() {
     return !!this._properties.isArticle;
   },
   set isArticle(val) {
     this._properties.isArticle = !!val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's word count.
    * @type integer
    */
   get wordCount() {
     return this._properties.wordCount;
   },
   set wordCount(val) {
     this._properties.wordCount = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * Whether the item is unread.
    * @type boolean
    */
   get unread() {
     return !!this._properties.unread;
   },
   set unread(val) {
     this._properties.unread = !!val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The date the item was added.
    * @type Date
    */
   get addedOn() {
     return this._properties.addedOn ?
            new Date(this._properties.addedOn) :
            undefined;
   },
   set addedOn(val) {
     this._properties.addedOn = val.valueOf();
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The date the item was stored.
    * @type Date
    */
   get storedOn() {
     return this._properties.storedOn ?
            new Date(this._properties.storedOn) :
            undefined;
   },
   set storedOn(val) {
     this._properties.storedOn = val.valueOf();
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The GUID of the device that marked the item read.
    * @type string
    */
   get markedReadBy() {
     return this._properties.markedReadBy;
   },
   set markedReadBy(val) {
     this._properties.markedReadBy = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The date the item marked read.
    * @type Date
    */
   get markedReadOn() {
     return this._properties.markedReadOn ?
            new Date(this._properties.markedReadOn) :
            undefined;
   },
   set markedReadOn(val) {
     this._properties.markedReadOn = val.valueOf();
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
    * The item's read position.
    * @param integer
    */
   get readPosition() {
     return this._properties.readPosition;
   },
   set readPosition(val) {
     this._properties.readPosition = val;
-    if (this.list) {
-      this.commit();
-    }
   },
 
   /**
-   * Sets the given properties of the item, optionally calling commit().
+   * Sets the given properties of the item, optionally calling list.updateItem().
    *
    * @param props A simple object containing the properties to set.
-   * @param commit If true, commit() is called.
-   * @return Promise<null> If commit is true, resolved when the commit
+   * @param update If true, updateItem() is called for this item.
+   * @return Promise<null> If update is true, resolved when the update
    *         completes; otherwise resolved immediately.
    */
-  setProperties: Task.async(function* (props, commit=true) {
+  setProperties: Task.async(function* (props, update=true) {
     for (let name in props) {
       this._properties[name] = props[name];
     }
-    if (commit) {
-      yield this.commit();
+    // make sure everything is normalized.
+    normalizeReadingListProperties(this._properties);
+    if (update) {
+      yield this.list.updateItem(this);
     }
   }),
 
   /**
    * Deletes the item from its list.
    *
    * @return Promise<null> Resolved when the list has been updated.
    */
   delete: Task.async(function* () {
     this._ensureBelongsToList();
     yield this.list.deleteItem(this);
     this.delete = () => Promise.reject("The item has already been deleted");
   }),
 
-  /**
-   * Notifies the item's list that the item has changed so that the list can
-   * update itself.
-   *
-   * @return Promise<null> Resolved when the list has been updated.
-   */
-  commit: Task.async(function* () {
-    this._ensureBelongsToList();
-    yield this.list.updateItem(this);
-  }),
-
   toJSON() {
     return this._properties;
   },
 
   _ensureBelongsToList() {
     if (!this.list) {
       throw new Error("The item must belong to a reading list");
     }
@@ -850,16 +842,33 @@ ReadingListItemIterator.prototype = {
 
   _ensureValid() {
     if (this.invalid) {
       throw new Error("The iterator has been invalidated");
     }
   },
 };
 
+/**
+ * Normalize a URI, stripping away extraneous parts we don't want to store
+ * or compare against.
+ *
+ * @param {nsIURI/String} uri - URI to normalize.
+ * @returns {nsIURI} Cloned and normalized version of the input URI.
+ */
+function normalizeURI(uri) {
+  if (typeof uri == "string") {
+    uri = Services.io.newURI(uri, "", null);
+  }
+  uri = uri.cloneIgnoringRef();
+  try {
+    uri.userPass = "";
+  } catch (ex) {} // Not all nsURI impls (eg, nsSimpleURI) support .userPass
+  return uri;
+};
 
 function stripNonItemProperties(item) {
   let obj = {};
   for (let name of ITEM_BASIC_PROPERTY_NAMES) {
     if (name in item) {
       obj[name] = item[name];
     }
   }
@@ -880,16 +889,34 @@ function hash(str) {
     join("");
   return hexStr;
 }
 
 function clone(obj) {
   return Cu.cloneInto(obj, {}, { cloneFunctions: false });
 }
 
+/**
+ * Get page metadata from the content document in a given <xul:browser>.
+ * @see PageMetadata.jsm
+ *
+ * @param {<xul:browser>} browser - Browser element for the document.
+ * @returns {Promise} Promise that is fulfilled with an object describing the metadata.
+ */
+function getMetadataFromBrowser(browser) {
+  let mm = browser.messageManager;
+  return new Promise(resolve => {
+    function handleResult(msg) {
+      mm.removeMessageListener("PageMetadata:PageDataResult", handleResult);
+      resolve(msg.json);
+    }
+    mm.addMessageListener("PageMetadata:PageDataResult", handleResult);
+    mm.sendAsyncMessage("PageMetadata:GetPageData");
+  });
+}
 
 Object.defineProperty(this, "ReadingList", {
   get() {
     if (!this._singleton) {
       let store = new SQLiteStore("reading-list-temp.sqlite");
       this._singleton = new ReadingListImpl(store);
     }
     return this._singleton;

--- a/browser/components/readinglist/test/xpcshell/test_ReadingList.js
+++ b/browser/components/readinglist/test/xpcshell/test_ReadingList.js
@@ -117,20 +117,21 @@ add_task(function* constraints() {
     yield gList.addItem(item);
   }
   catch (e) {
     err = e;
   }
   checkError(err);
 
   // update an item with an existing url
-  item.guid = gItems[1].guid;
+  let rlitem = yield gList.getItemForURL(gItems[0].url);
+  rlitem.guid = gItems[1].guid;
   err = null;
   try {
-    yield gList.updateItem(item);
+    yield gList.updateItem(rlitem);
   }
   catch (e) {
     err = e;
   }
   checkError(err);
 
   // add a new item with an existing resolvedURL
   item = kindOfClone(gItems[0]);
@@ -140,59 +141,58 @@ add_task(function* constraints() {
     yield gList.addItem(item);
   }
   catch (e) {
     err = e;
   }
   checkError(err);
 
   // update an item with an existing resolvedURL
-  item.url = gItems[1].url;
+  rlitem = yield gList.getItemForURL(gItems[0].url);
+  rlitem.url = gItems[1].url;
   err = null;
   try {
-    yield gList.updateItem(item);
+    yield gList.updateItem(rlitem);
   }
   catch (e) {
     err = e;
   }
   checkError(err);
 
   // add a new item with no guid, which is allowed
   item = kindOfClone(gItems[0]);
   delete item.guid;
   err = null;
+  let rlitem1;
   try {
-    yield gList.addItem(item);
+    rlitem1 = yield gList.addItem(item);
   }
   catch (e) {
     err = e;
   }
   Assert.ok(!err, err ? err.message : undefined);
-  let item1 = item;
 
   // add a second item with no guid, which is allowed
   item = kindOfClone(gItems[1]);
   delete item.guid;
   err = null;
+  let rlitem2;
   try {
-    yield gList.addItem(item);
+    rlitem2 = yield gList.addItem(item);
   }
   catch (e) {
     err = e;
   }
   Assert.ok(!err, err ? err.message : undefined);
-  let item2 = item;
 
   // Delete both items since other tests assume the store contains only gItems.
-  item1.list = gList;
-  item2.list = gList;
-  yield gList.deleteItem(item1);
-  yield gList.deleteItem(item2);
+  yield gList.deleteItem(rlitem1);
+  yield gList.deleteItem(rlitem2);
   let items = [];
-  yield gList.forEachItem(i => items.push(i), { url: [item1.url, item2.url] });
+  yield gList.forEachItem(i => items.push(i), { url: [rlitem1.url, rlitem2.url] });
   Assert.equal(items.length, 0);
 
   // add a new item with no url
   item = kindOfClone(gItems[0]);
   delete item.url;
   err = null;
   try {
     yield gList.addItem(item);
@@ -508,25 +508,22 @@ add_task(function* iterator_forEach_prom
 
 add_task(function* updateItem() {
   // get an item
   let items = [];
   yield gList.forEachItem(i => items.push(i), {
     guid: gItems[0].guid,
   });
   Assert.equal(items.length, 1);
-  let item = {
-    _properties: items[0]._properties,
-    list: items[0].list,
-  };
+  let item = items[0];
 
   // update its title
   let newTitle = "updateItem new title";
   Assert.notEqual(item.title, newTitle);
-  item._properties.title = newTitle;
+  item.title = newTitle;
   yield gList.updateItem(item);
 
   // get the item again
   items = [];
   yield gList.forEachItem(i => items.push(i), {
     guid: gItems[0].guid,
   });
   Assert.equal(items.length, 1);
@@ -537,92 +534,98 @@ add_task(function* updateItem() {
 add_task(function* item_setProperties() {
   // get an item
   let iter = gList.iterator({
     sort: "guid",
   });
   let item = (yield iter.items(1))[0];
   Assert.ok(item);
 
-  // item.setProperties(commit=false).  After fetching the item again, its title
+  // item.setProperties(update=false).  After fetching the item again, its title
   // should be the old title.
   let oldTitle = item.title;
   let newTitle = "item_setProperties title 1";
   Assert.notEqual(oldTitle, newTitle);
   item.setProperties({ title: newTitle }, false);
   Assert.equal(item.title, newTitle);
   iter = gList.iterator({
     sort: "guid",
   });
   let sameItem = (yield iter.items(1))[0];
   Assert.ok(item === sameItem);
   Assert.equal(sameItem.title, oldTitle);
 
-  // item.setProperties(commit=true).  After fetching the item again, its title
+  // item.setProperties(update=true).  After fetching the item again, its title
   // should be the new title.
   newTitle = "item_setProperties title 2";
   item.setProperties({ title: newTitle }, true);
   Assert.equal(item.title, newTitle);
   iter = gList.iterator({
     sort: "guid",
   });
   sameItem = (yield iter.items(1))[0];
   Assert.ok(item === sameItem);
   Assert.equal(sameItem.title, newTitle);
 
   // Set item.title directly.  After fetching the item again, its title should
   // be the new title.
   newTitle = "item_setProperties title 3";
   item.title = newTitle;
+  gList.updateItem(item);
   Assert.equal(item.title, newTitle);
   iter = gList.iterator({
     sort: "guid",
   });
   sameItem = (yield iter.items(1))[0];
   Assert.ok(item === sameItem);
   Assert.equal(sameItem.title, newTitle);
 });
 
 add_task(function* listeners() {
+  Assert.equal((yield gList.count()), gItems.length);
   // add an item
   let resolve;
   let listenerPromise = new Promise(r => resolve = r);
   let listener = {
     onItemAdded: resolve,
   };
   gList.addListener(listener);
   let item = kindOfClone(gItems[0]);
   let items = yield Promise.all([listenerPromise, gList.addItem(item)]);
   Assert.ok(items[0]);
   Assert.ok(items[0] === items[1]);
   gList.removeListener(listener);
+  Assert.equal((yield gList.count()), gItems.length + 1);
 
   // update an item
   listenerPromise = new Promise(r => resolve = r);
   listener = {
     onItemUpdated: resolve,
   };
   gList.addListener(listener);
   items[0].title = "listeners new title";
+  gList.updateItem(items[0]);
   let listenerItem = yield listenerPromise;
   Assert.ok(listenerItem);
   Assert.ok(listenerItem === items[0]);
   gList.removeListener(listener);
+  Assert.equal((yield gList.count()), gItems.length + 1);
 
   // delete an item
   listenerPromise = new Promise(r => resolve = r);
   listener = {
     onItemDeleted: resolve,
   };
   gList.addListener(listener);
   items[0].delete();
   listenerItem = yield listenerPromise;
   Assert.ok(listenerItem);
   Assert.ok(listenerItem === items[0]);
   gList.removeListener(listener);
+  Assert.equal((yield gList.count()), gItems.length);
 });
 
 // This test deletes items so it should probably run last.
 add_task(function* deleteItem() {
   // delete first item with item.delete()
   let iter = gList.iterator({
     sort: "guid",
   });
@@ -633,27 +636,27 @@ add_task(function* deleteItem() {
   Assert.equal((yield gList.count()), gItems.length - 1);
   let items = [];
   yield gList.forEachItem(i => items.push(i), {
     sort: "guid",
   });
   checkItems(items, gItems.slice(1));
 
   // delete second item with list.deleteItem()
-  yield gList.deleteItem(gItems[1]);
+  yield gList.deleteItem(items[0]);
   gItems[1].list = null;
   Assert.equal((yield gList.count()), gItems.length - 2);
   items = [];
   yield gList.forEachItem(i => items.push(i), {
     sort: "guid",
   });
   checkItems(items, gItems.slice(2));
 
   // delete third item with list.deleteItem()
-  yield gList.deleteItem(gItems[2]);
+  yield gList.deleteItem(items[0]);
   gItems[2].list = null;
   Assert.equal((yield gList.count()), gItems.length - 3);
   items = [];
   yield gList.forEachItem(i => items.push(i), {
     sort: "guid",
   });
   checkItems(items, gItems.slice(3));
 });
@@ -668,17 +671,17 @@ function checkItems(actualItems, expecte
       }
     }
     Assert.equal(actualItems[i].list, expectedItems[i].list);
   }
 }
 
 function checkError(err) {
   Assert.ok(err);
-  Assert.ok(err instanceof Cu.getGlobalForObject(Sqlite).Error);
+  Assert.ok(err instanceof Cu.getGlobalForObject(Sqlite).Error, err);
 }
 
 function kindOfClone(item) {
   let newItem = {};
   for (let prop in item) {
     newItem[prop] = item[prop];
     if (typeof(newItem[prop]) == "string") {
       newItem[prop] += " -- make this string different";

--- a/browser/modules/ReaderParent.jsm
+++ b/browser/modules/ReaderParent.jsm
@@ -55,22 +55,22 @@ let ReaderParent = {
         });
         break;
 
       case "Reader:FaviconRequest": {
         // XXX: To implement.
         break;
       }
       case "Reader:ListStatusRequest":
-        ReadingList.count(message.data).then(count => {
+        ReadingList.containsURL(message.data.url).then(inList => {
           let mm = message.target.messageManager
           // Make sure the target browser is still alive before trying to send data back.
           if (mm) {
             mm.sendAsyncMessage("Reader:ListStatusData",
-                                { inReadingList: !!count, url: message.data.url });
+                                { inReadingList: inList, url: message.data.url });
           }
         });
         break;
 
       case "Reader:RemoveFromList":
         // We need to get the "real" item to delete it.
         ReadingList.getItemForURL(message.data.url).then(item => {
           ReadingList.deleteItem(item)

--- a/browser/themes/linux/browser.css
+++ b/browser/themes/linux/browser.css
@@ -1624,16 +1624,18 @@ richlistitem[type~="action"][actiontype=
   -moz-image-region: rect(28px, 28px, 42px, 14px);
 }
 
 /* Popup blocker button */
 #page-report-button {
   list-style-image: url("chrome://browser/skin/Info.png");
 }
 
+%include ../shared/readinglist.inc.css
+
 /* Reader mode button */
 
 #reader-mode-button {
   -moz-appearance: none;
   padding: 0;
   list-style-image: url("chrome://browser/skin/reader-mode-16.png");
   -moz-image-region: rect(0, 16px, 16px, 0);
 }

--- a/browser/themes/linux/jar.mn
+++ b/browser/themes/linux/jar.mn
@@ -86,16 +86,17 @@ browser.jar:
   skin/classic/browser/Toolbar-inverted.png
   skin/classic/browser/Toolbar-small.png
   skin/classic/browser/undoCloseTab.png                        (../shared/undoCloseTab.png)
   skin/classic/browser/urlbar-arrow.png
   skin/classic/browser/session-restore.svg                  (../shared/incontent-icons/session-restore.svg)
   skin/classic/browser/tab-crashed.svg                      (../shared/incontent-icons/tab-crashed.svg)
   skin/classic/browser/welcome-back.svg                     (../shared/incontent-icons/welcome-back.svg)
   skin/classic/browser/reader-mode-16.png             (../shared/reader/reader-mode-16.png)
+  skin/classic/browser/readinglist/icons.svg          (../shared/readinglist/icons.svg)
   skin/classic/browser/readinglist/readinglist-icon.svg (../shared/readinglist/readinglist-icon.svg)
   skin/classic/browser/readinglist/sidebar.css        (../shared/readinglist/sidebar.css)
   skin/classic/browser/webRTC-shareDevice-16.png
   skin/classic/browser/webRTC-shareDevice-64.png
   skin/classic/browser/webRTC-sharingDevice-16.png    (../shared/webrtc/webRTC-sharingDevice-16.png)
   skin/classic/browser/webRTC-shareMicrophone-16.png
   skin/classic/browser/webRTC-shareMicrophone-64.png
   skin/classic/browser/webRTC-sharingMicrophone-16.png (../shared/webrtc/webRTC-sharingMicrophone-16.png)

--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -2518,16 +2518,18 @@ richlistitem[type~="action"][actiontype=
   }
 
   #page-report-button:hover:active,
   #page-report-button[open="true"] {
     -moz-image-region: rect(0, 64px, 32px, 32px);
   }
 }
 
+%include ../shared/readinglist.inc.css
+
 /* Reader mode button */
 
 #reader-mode-button {
   -moz-appearance: none;
   padding: 0;
   list-style-image: url("chrome://browser/skin/reader-mode-16.png");
   -moz-image-region: rect(0, 16px, 16px, 0);
 }

--- a/browser/themes/osx/jar.mn
+++ b/browser/themes/osx/jar.mn
@@ -137,16 +137,17 @@ browser.jar:
   skin/classic/browser/urlbar-arrow@2x.png
   skin/classic/browser/urlbar-popup-blocked.png
   skin/classic/browser/urlbar-popup-blocked@2x.png
   skin/classic/browser/session-restore.svg            (../shared/incontent-icons/session-restore.svg)
   skin/classic/browser/tab-crashed.svg                (../shared/incontent-icons/tab-crashed.svg)
   skin/classic/browser/welcome-back.svg               (../shared/incontent-icons/welcome-back.svg)
   skin/classic/browser/reader-mode-16.png             (../shared/reader/reader-mode-16.png)
   skin/classic/browser/reader-mode-16@2x.png          (../shared/reader/reader-mode-16@2x.png)
+  skin/classic/browser/readinglist/icons.svg          (../shared/readinglist/icons.svg)
   skin/classic/browser/readinglist/readinglist-icon.svg (../shared/readinglist/readinglist-icon.svg)
   skin/classic/browser/readinglist/sidebar.css        (../shared/readinglist/sidebar.css)
   skin/classic/browser/webRTC-shareDevice-16.png
   skin/classic/browser/webRTC-shareDevice-16@2x.png
   skin/classic/browser/webRTC-shareDevice-64.png
   skin/classic/browser/webRTC-shareDevice-64@2x.png
   skin/classic/browser/webRTC-sharingDevice-16.png    (../shared/webrtc/webRTC-sharingDevice-16.png)
   skin/classic/browser/webRTC-sharingDevice-16@2x.png (../shared/webrtc/webRTC-sharingDevice-16@2x.png)

new file mode 100644
--- /dev/null
+++ b/browser/themes/shared/readinglist.inc.css
@@ -0,0 +1,38 @@
+/* Reading List button */
+
+#readinglist-addremove-button {
+  -moz-appearance: none;
+  border: none;
+  list-style-image: url("chrome://browser/skin/readinglist/icons.svg#addpage");
+  padding: 3px;
+}
+
+#readinglist-addremove-button:hover {
+  border: none;
+}
+
+#readinglist-addremove-button > .toolbarbutton-icon {
+  width: 16px;
+  height: 16px
+}
+
+#readinglist-addremove-button:not([already-added="true"]):hover {
+  list-style-image: url("chrome://browser/skin/readinglist/icons.svg#addpage-hover");
+}
+
+#readinglist-addremove-button:not([already-added="true"]):active {
+  list-style-image: url("chrome://browser/skin/readinglist/icons.svg#addpage-active");
+}
+
+#readinglist-addremove-button[already-added="true"] {
+  list-style-image: url("chrome://browser/skin/readinglist/icons.svg#alreadyadded");
+}
+
+#readinglist-addremove-button[already-added="true"]:hover {
+  list-style-image: url("chrome://browser/skin/readinglist/icons.svg#alreadyadded-hover");
+}
+
+#readinglist-addremove-button[already-added="true"]:active {
+  list-style-image: url("chrome://browser/skin/readinglist/icons.svg#alreadyadded-active");
+}
+

new file mode 100644
--- /dev/null
+++ b/browser/themes/shared/readinglist/icons.svg
@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<svg xmlns="http://www.w3.org/2000/svg"
+     xmlns:xlink="http://www.w3.org/1999/xlink"
+     viewBox="0 0 16 16"
+     xml:space="preserve">
+
+  <defs>
+    <style type="text/css">
+      use:not(:target) {
+        display: none;
+      }
+
+      #addpage {
+        fill: #808080;
+      }
+      #addpage-hover {
+        fill: #555555;
+      }
+      #addpage-active {
+        fill: #0095DD;
+      }
+
+      #alreadyadded {
+        fill: #0095DD;
+      }
+      #alreadyadded-hover {
+        fill: #555555;
+      }
+      #alreadyadded-active {
+        fill: #808080;
+      }
+    </style>
+
+    <mask id="plus-mask">
+      <rect width="100%" height="100%" fill="white"/>
+      <rect x="4" y="7.5" width="8" height="1"/>
+      <rect x="7.5" y="4" width="1" height="8"/>
+    </mask>
+
+    <g id="addpage-shape">
+      <circle cx="8" cy="8" r="7" mask="url(#plus-mask)"/>
+    </g>
+
+  </defs>
+
+  <use id="addpage"                 xlink:href="#addpage-shape"/>
+  <use id="addpage-hover"           xlink:href="#addpage-shape"/>
+  <use id="addpage-active"          xlink:href="#addpage-shape"/>
+
+  <use id="alreadyadded"            xlink:href="#addpage-shape"/>
+  <use id="alreadyadded-hover"      xlink:href="#addpage-shape"/>
+  <use id="alreadyadded-active"     xlink:href="#addpage-shape"/>
+
+</svg>

--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -1571,16 +1571,18 @@ richlistitem[type~="action"][actiontype=
   -moz-image-region: rect(0, 32px, 16px, 16px);
 }
 
 #page-report-button:hover:active,
 #page-report-button[open="true"] {
   -moz-image-region: rect(0, 48px, 16px, 32px);
 }
 
+%include ../shared/readinglist.inc.css
+
 /* Reader mode button */
 
 #reader-mode-button {
   -moz-appearance: none;
   padding: 0;
   list-style-image: url("chrome://browser/skin/reader-mode-16.png");
   -moz-image-region: rect(0, 16px, 16px, 0);
 }

--- a/browser/themes/windows/jar.mn
+++ b/browser/themes/windows/jar.mn
@@ -105,16 +105,17 @@ browser.jar:
         skin/classic/browser/undoCloseTab@2x.png                     (../shared/undoCloseTab@2x.png)
         skin/classic/browser/urlbar-arrow.png
         skin/classic/browser/urlbar-popup-blocked.png
         skin/classic/browser/urlbar-history-dropmarker.png
         skin/classic/browser/session-restore.svg                     (../shared/incontent-icons/session-restore.svg)
         skin/classic/browser/tab-crashed.svg                         (../shared/incontent-icons/tab-crashed.svg)
         skin/classic/browser/welcome-back.svg                        (../shared/incontent-icons/welcome-back.svg)
         skin/classic/browser/reader-mode-16.png                      (../shared/reader/reader-mode-16.png)
+        skin/classic/browser/readinglist/icons.svg                   (../shared/readinglist/icons.svg)
         skin/classic/browser/readinglist/readinglist-icon.svg        (../shared/readinglist/readinglist-icon.svg)
         skin/classic/browser/readinglist/sidebar.css                 (../shared/readinglist/sidebar.css)
         skin/classic/browser/notification-pluginNormal.png           (../shared/plugins/notification-pluginNormal.png)
         skin/classic/browser/notification-pluginAlert.png            (../shared/plugins/notification-pluginAlert.png)
         skin/classic/browser/notification-pluginBlocked.png          (../shared/plugins/notification-pluginBlocked.png)
         skin/classic/browser/webRTC-shareDevice-16.png
         skin/classic/browser/webRTC-shareDevice-64.png
         skin/classic/browser/webRTC-sharingDevice-16.png             (../shared/webrtc/webRTC-sharingDevice-16.png)
@@ -572,16 +573,17 @@ browser.jar:
         skin/classic/aero/browser/undoCloseTab@2x.png                     (../shared/undoCloseTab@2x.png)
         skin/classic/aero/browser/urlbar-arrow.png
         skin/classic/aero/browser/urlbar-popup-blocked.png
         skin/classic/aero/browser/urlbar-history-dropmarker.png
         skin/classic/aero/browser/session-restore.svg               (../shared/incontent-icons/session-restore.svg)
         skin/classic/aero/browser/tab-crashed.svg                   (../shared/incontent-icons/tab-crashed.svg)
         skin/classic/aero/browser/welcome-back.svg                  (../shared/incontent-icons/welcome-back.svg)
         skin/classic/aero/browser/reader-mode-16.png                (../shared/reader/reader-mode-16.png)
+        skin/classic/aero/browser/readinglist/icons.svg             (../shared/readinglist/icons.svg)
         skin/classic/aero/browser/readinglist/readinglist-icon.svg  (../shared/readinglist/readinglist-icon.svg)
         skin/classic/aero/browser/readinglist/sidebar.css           (../shared/readinglist/sidebar.css)
         skin/classic/aero/browser/notification-pluginNormal.png     (../shared/plugins/notification-pluginNormal.png)
         skin/classic/aero/browser/notification-pluginAlert.png      (../shared/plugins/notification-pluginAlert.png)
         skin/classic/aero/browser/notification-pluginBlocked.png    (../shared/plugins/notification-pluginBlocked.png)
         skin/classic/aero/browser/webRTC-shareDevice-16.png
         skin/classic/aero/browser/webRTC-shareDevice-64.png
         skin/classic/aero/browser/webRTC-sharingDevice-16.png             (../shared/webrtc/webRTC-sharingDevice-16.png)