diff --git a/browser/modules/DirectoryLinksProvider.jsm b/browser/modules/DirectoryLinksProvider.jsm
index 47e8a6ab9a66..9385c0921c9e 100644
--- a/browser/modules/DirectoryLinksProvider.jsm
+++ b/browser/modules/DirectoryLinksProvider.jsm
@@ -47,6 +47,12 @@ const PREF_DIRECTORY_PING = "browser.newtabpage.directory.ping";
 // The preference that tells if newtab is enhanced
 const PREF_NEWTAB_ENHANCED = "browser.newtabpage.enhanced";
 
+// Only allow link urls that are http(s)
+const ALLOWED_LINK_SCHEMES = new Set(["http", "https"]);
+
+// Only allow link image urls that are https or data
+const ALLOWED_IMAGE_SCHEMES = new Set(["https", "data"]);
+
 // The frecency of a directory link
 const DIRECTORY_FRECENCY = 1000;
 
@@ -359,6 +365,24 @@ let DirectoryLinksProvider = {
            this._enhancedLinks.get(NewTabUtils.extractSite(link.url));
   },
 
+  /**
+   * Check if a url's scheme is in a Set of allowed schemes
+   */
+  isURLAllowed: function DirectoryLinksProvider_isURLAllowed(url, allowed) {
+    // Assume no url is an allowed url
+    if (!url) {
+      return true;
+    }
+
+    let scheme = "";
+    try {
+      // A malformed url will not be allowed
+      scheme = Services.io.newURI(url, null, null).scheme;
+    }
+    catch(ex) {}
+    return allowed.has(scheme);
+  },
+
   /**
    * Gets the current set of directory links.
    * @param aCallback The function that the array of links is passed to.
@@ -368,8 +392,12 @@ let DirectoryLinksProvider = {
       // Reset the cache of enhanced images for this new set of links
       this._enhancedLinks.clear();
 
-      // all directory links have a frecency of DIRECTORY_FRECENCY
-      return rawLinks.map((link, position) => {
+      return rawLinks.filter(link => {
+        // Make sure the link url is allowed and images too if they exist
+        return this.isURLAllowed(link.url, ALLOWED_LINK_SCHEMES) &&
+               this.isURLAllowed(link.imageURI, ALLOWED_IMAGE_SCHEMES) &&
+               this.isURLAllowed(link.enhancedImageURI, ALLOWED_IMAGE_SCHEMES);
+      }).map((link, position) => {
         // Stash the enhanced image for the site
         if (link.enhancedImageURI) {
           this._enhancedLinks.set(NewTabUtils.extractSite(link.url), link);
diff --git a/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js b/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js
index 52e68628271b..72c28953fd43 100644
--- a/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js
+++ b/browser/modules/test/xpcshell/test_DirectoryLinksProvider.js
@@ -556,11 +556,74 @@ add_task(function test_DirectoryLinksProvider_getLinksFromCorruptedFile() {
   yield promiseCleanDirectoryLinksProvider();
 });
 
+add_task(function test_DirectoryLinksProvider_getAllowedLinks() {
+  let data = {"en-US": [
+    {url: "ftp://example.com"},
+    {url: "http://example.net"},
+    {url: "javascript:5"},
+    {url: "https://example.com"},
+    {url: "httpJUNKjavascript:42"},
+    {url: "data:text/plain,hi"},
+    {url: "http/bork:eh"},
+  ]};
+  let dataURI = 'data:application/json,' + JSON.stringify(data);
+  yield promiseSetupDirectoryLinksProvider({linksURL: dataURI});
+
+  let links = yield fetchData();
+  do_check_eq(links.length, 2);
+
+  // The only remaining url should be http and https
+  do_check_eq(links[0].url, data["en-US"][1].url);
+  do_check_eq(links[1].url, data["en-US"][3].url);
+});
+
+add_task(function test_DirectoryLinksProvider_getAllowedImages() {
+  let data = {"en-US": [
+    {url: "http://example.com", imageURI: "ftp://example.com"},
+    {url: "http://example.com", imageURI: "http://example.net"},
+    {url: "http://example.com", imageURI: "javascript:5"},
+    {url: "http://example.com", imageURI: "https://example.com"},
+    {url: "http://example.com", imageURI: "httpJUNKjavascript:42"},
+    {url: "http://example.com", imageURI: "data:text/plain,hi"},
+    {url: "http://example.com", imageURI: "http/bork:eh"},
+  ]};
+  let dataURI = 'data:application/json,' + JSON.stringify(data);
+  yield promiseSetupDirectoryLinksProvider({linksURL: dataURI});
+
+  let links = yield fetchData();
+  do_check_eq(links.length, 2);
+
+  // The only remaining images should be https and data
+  do_check_eq(links[0].imageURI, data["en-US"][3].imageURI);
+  do_check_eq(links[1].imageURI, data["en-US"][5].imageURI);
+});
+
+add_task(function test_DirectoryLinksProvider_getAllowedEnhancedImages() {
+  let data = {"en-US": [
+    {url: "http://example.com", enhancedImageURI: "ftp://example.com"},
+    {url: "http://example.com", enhancedImageURI: "http://example.net"},
+    {url: "http://example.com", enhancedImageURI: "javascript:5"},
+    {url: "http://example.com", enhancedImageURI: "https://example.com"},
+    {url: "http://example.com", enhancedImageURI: "httpJUNKjavascript:42"},
+    {url: "http://example.com", enhancedImageURI: "data:text/plain,hi"},
+    {url: "http://example.com", enhancedImageURI: "http/bork:eh"},
+  ]};
+  let dataURI = 'data:application/json,' + JSON.stringify(data);
+  yield promiseSetupDirectoryLinksProvider({linksURL: dataURI});
+
+  let links = yield fetchData();
+  do_check_eq(links.length, 2);
+
+  // The only remaining enhancedImages should be http and https and data
+  do_check_eq(links[0].enhancedImageURI, data["en-US"][3].enhancedImageURI);
+  do_check_eq(links[1].enhancedImageURI, data["en-US"][5].enhancedImageURI);
+});
+
 add_task(function test_DirectoryLinksProvider_getEnhancedLink() {
   let data = {"en-US": [
-    {url: "http://example.net", enhancedImageURI: "net1"},
-    {url: "http://example.com", enhancedImageURI: "com1"},
-    {url: "http://example.com", enhancedImageURI: "com2"},
+    {url: "http://example.net", enhancedImageURI: "data:,net1"},
+    {url: "http://example.com", enhancedImageURI: "data:,com1"},
+    {url: "http://example.com", enhancedImageURI: "data:,com2"},
   ]};
   let dataURI = 'data:application/json,' + JSON.stringify(data);
   yield promiseSetupDirectoryLinksProvider({linksURL: dataURI});
@@ -574,20 +637,20 @@ add_task(function test_DirectoryLinksProvider_getEnhancedLink() {
   }
 
   // Get the expected image for the same site
-  checkEnhanced("http://example.net/", "net1");
-  checkEnhanced("http://example.net/path", "net1");
-  checkEnhanced("https://www.example.net/", "net1");
-  checkEnhanced("https://www3.example.net/", "net1");
+  checkEnhanced("http://example.net/", "data:,net1");
+  checkEnhanced("http://example.net/path", "data:,net1");
+  checkEnhanced("https://www.example.net/", "data:,net1");
+  checkEnhanced("https://www3.example.net/", "data:,net1");
 
   // Get the image of the last entry
-  checkEnhanced("http://example.com", "com2");
+  checkEnhanced("http://example.com", "data:,com2");
 
   // Get the inline enhanced image
   let inline = DirectoryLinksProvider.getEnhancedLink({
     url: "http://example.com/echo",
-    enhancedImageURI: "echo",
+    enhancedImageURI: "data:,echo",
   });
-  do_check_eq(inline.enhancedImageURI, "echo");
+  do_check_eq(inline.enhancedImageURI, "data:,echo");
   do_check_eq(inline.url, "http://example.com/echo");
 
   // Undefined for not enhanced
@@ -598,14 +661,14 @@ add_task(function test_DirectoryLinksProvider_getEnhancedLink() {
 
   // Make sure old data is not cached
   data = {"en-US": [
-    {url: "http://example.com", enhancedImageURI: "fresh"},
+    {url: "http://example.com", enhancedImageURI: "data:,fresh"},
   ]};
   dataURI = 'data:application/json,' + JSON.stringify(data);
   yield promiseSetupDirectoryLinksProvider({linksURL: dataURI});
   links = yield fetchData();
   do_check_eq(links.length, 1);
   checkEnhanced("http://example.net", undefined);
-  checkEnhanced("http://example.com", "fresh");
+  checkEnhanced("http://example.com", "data:,fresh");
 });
 
 add_task(function test_DirectoryLinksProvider_setDefaultEnhanced() {
diff --git a/mobile/android/base/BrowserApp.java b/mobile/android/base/BrowserApp.java
index c34a5f065158..2da84a9df711 100644
--- a/mobile/android/base/BrowserApp.java
+++ b/mobile/android/base/BrowserApp.java
@@ -267,6 +267,9 @@ public class BrowserApp extends GeckoApp
         Log.d(LOGTAG, "BrowserApp.onTabChanged: " + tab.getId() + ": " + msg);
         switch(msg) {
             case LOCATION_CHANGE:
+                if (Tabs.getInstance().isSelectedTab(tab)) {
+                    maybeCancelFaviconLoad(tab);
+                }
                 // fall through
             case SELECTED:
                 if (Tabs.getInstance().isSelectedTab(tab)) {
@@ -290,7 +293,16 @@ public class BrowserApp extends GeckoApp
                 }
                 break;
             case PAGE_SHOW:
-                tab.loadFavicon();
+                loadFavicon(tab);
+                break;
+            case LINK_FAVICON:
+                // If tab is not loading and the favicon is updated, we
+                // want to load the image straight away. If tab is still
+                // loading, we only load the favicon once the page's content
+                // is fully loaded.
+                if (tab.getState() != Tab.STATE_LOADING) {
+                    loadFavicon(tab);
+                }
                 break;
             case BOOKMARK_ADDED:
                 showBookmarkAddedToast();
@@ -1811,6 +1823,41 @@ public class BrowserApp extends GeckoApp
             && mHomePagerContainer != null && mHomePagerContainer.getVisibility() == View.VISIBLE);
     }
 
+    /* Favicon stuff. */
+    private static OnFaviconLoadedListener sFaviconLoadedListener = new OnFaviconLoadedListener() {
+        @Override
+        public void onFaviconLoaded(String pageUrl, String faviconURL, Bitmap favicon) {
+            // If we failed to load a favicon, we use the default favicon instead.
+            Tabs.getInstance()
+                .updateFaviconForURL(pageUrl,
+                                     (favicon == null) ? Favicons.defaultFavicon : favicon);
+        }
+    };
+
+    private void loadFavicon(final Tab tab) {
+        maybeCancelFaviconLoad(tab);
+
+        final int tabFaviconSize = getResources().getDimensionPixelSize(R.dimen.browser_toolbar_favicon_size);
+
+        int flags = (tab.isPrivate() || tab.getErrorType() != Tab.ErrorType.NONE) ? 0 : LoadFaviconTask.FLAG_PERSIST;
+        int id = Favicons.getSizedFavicon(getContext(), tab.getURL(), tab.getFaviconURL(), tabFaviconSize, flags, sFaviconLoadedListener);
+
+        tab.setFaviconLoadId(id);
+    }
+
+    private void maybeCancelFaviconLoad(Tab tab) {
+        int faviconLoadId = tab.getFaviconLoadId();
+
+        if (Favicons.NOT_LOADING == faviconLoadId) {
+            return;
+        }
+
+        // Cancel load task and reset favicon load state if it wasn't already
+        // in NOT_LOADING state.
+        Favicons.cancelFaviconLoad(faviconLoadId);
+        tab.setFaviconLoadId(Favicons.NOT_LOADING);
+    }
+
     /**
      * Enters editing mode with the current tab's URL. There might be no
      * tabs loaded by the time the user enters editing mode e.g. just after
diff --git a/mobile/android/base/GeckoAppShell.java b/mobile/android/base/GeckoAppShell.java
index a99b616b0dce..d015bb3dea92 100644
--- a/mobile/android/base/GeckoAppShell.java
+++ b/mobile/android/base/GeckoAppShell.java
@@ -34,8 +34,8 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.mozilla.gecko.AppConstants.Versions;
-import org.mozilla.gecko.favicons.Favicons;
 import org.mozilla.gecko.favicons.OnFaviconLoadedListener;
+import org.mozilla.gecko.favicons.decoders.FaviconDecoder;
 import org.mozilla.gecko.gfx.BitmapUtils;
 import org.mozilla.gecko.gfx.LayerView;
 import org.mozilla.gecko.gfx.PanZoomController;
@@ -810,24 +810,21 @@ public class GeckoAppShell
     // This is the entry point from nsIShellService.
     @WrapElementForJNI
     static void createShortcut(final String aTitle, final String aURI, final String aIconData) {
-        // We have the favicon data (base64) decoded on the background thread, callback here, then
-        // call the other createShortcut method with the decoded favicon.
-        // This is slightly contrived, but makes the images available to the favicon cache.
-        Favicons.getSizedFavicon(getContext(), aURI, aIconData, Integer.MAX_VALUE, 0,
-            new OnFaviconLoadedListener() {
-                @Override
-                public void onFaviconLoaded(String url, String faviconURL, Bitmap favicon) {
-                    createShortcut(aTitle, url, favicon);
-                }
+        ThreadUtils.postToBackgroundThread(new Runnable() {
+            @Override
+            public void run() {
+                // TODO: use the cache. Bug 961600.
+                Bitmap icon = FaviconDecoder.getMostSuitableBitmapFromDataURI(aIconData, getPreferredIconSize());
+                GeckoAppShell.doCreateShortcut(aTitle, aURI, icon);
             }
-        );
+        });
     }
 
     public static void createShortcut(final String aTitle, final String aURI, final Bitmap aBitmap) {
         ThreadUtils.postToBackgroundThread(new Runnable() {
             @Override
             public void run() {
-                doCreateShortcut(aTitle, aURI, aBitmap);
+                GeckoAppShell.doCreateShortcut(aTitle, aURI, aBitmap);
             }
         });
     }
diff --git a/mobile/android/base/Tab.java b/mobile/android/base/Tab.java
index fd862122e07c..a126bdf4bad5 100644
--- a/mobile/android/base/Tab.java
+++ b/mobile/android/base/Tab.java
@@ -9,7 +9,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.TreeSet;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -18,10 +17,6 @@ import org.json.JSONObject;
 import org.mozilla.gecko.db.BrowserContract.Bookmarks;
 import org.mozilla.gecko.db.BrowserDB;
 import org.mozilla.gecko.db.URLMetadata;
-import org.mozilla.gecko.favicons.Favicons;
-import org.mozilla.gecko.favicons.LoadFaviconTask;
-import org.mozilla.gecko.favicons.OnFaviconLoadedListener;
-import org.mozilla.gecko.favicons.RemoteFavicon;
 import org.mozilla.gecko.gfx.Layer;
 import org.mozilla.gecko.util.ThreadUtils;
 
@@ -47,9 +42,7 @@ public class Tab {
     private String mTitle;
     private Bitmap mFavicon;
     private String mFaviconUrl;
-
-    // The set of all available Favicons for this tab, sorted by attractiveness.
-    final TreeSet<RemoteFavicon> mAvailableFavicons = new TreeSet<>();
+    private int mFaviconSize;
     private boolean mHasFeeds;
     private boolean mHasOpenSearch;
     private final SiteIdentity mSiteIdentity;
@@ -372,81 +365,46 @@ public class Tab {
         return mHasTouchListeners;
     }
 
-    public synchronized void addFavicon(String faviconURL, int faviconSize, String mimeType) {
-        RemoteFavicon favicon = new RemoteFavicon(faviconURL, faviconSize, mimeType);
-
-        // Add this Favicon to the set of available Favicons.
-        synchronized (mAvailableFavicons) {
-            mAvailableFavicons.add(favicon);
-        }
+    public void setFaviconLoadId(int faviconLoadId) {
+        mFaviconLoadId = faviconLoadId;
     }
 
-    public void loadFavicon() {
-        // If we have a Favicon explicitly set, load it.
-        if (!mAvailableFavicons.isEmpty()) {
-            RemoteFavicon newFavicon = mAvailableFavicons.first();
+    public int getFaviconLoadId() {
+        return mFaviconLoadId;
+    }
 
-            // If the new Favicon is different, cancel the old load. Else, abort.
-            if (newFavicon.faviconUrl.equals(mFaviconUrl)) {
-                return;
-            }
-
-            Favicons.cancelFaviconLoad(mFaviconLoadId);
-            mFaviconUrl = newFavicon.faviconUrl;
-        } else {
-            // Otherwise, fallback to the default Favicon.
-            mFaviconUrl = null;
+    /**
+     * Returns true if the favicon changed.
+     */
+    public boolean updateFavicon(Bitmap favicon) {
+        if (mFavicon == favicon) {
+            return false;
         }
+        mFavicon = favicon;
+        return true;
+    }
 
-        int flags = (isPrivate() || mErrorType != ErrorType.NONE) ? 0 : LoadFaviconTask.FLAG_PERSIST;
-        mFaviconLoadId = Favicons.getSizedFavicon(mAppContext, mUrl, mFaviconUrl, Favicons.browserToolbarFaviconSize, flags,
-                new OnFaviconLoadedListener() {
-                    @Override
-                    public void onFaviconLoaded(String pageUrl, String faviconURL, Bitmap favicon) {
-                        // The tab might be pointing to another URL by the time the
-                        // favicon is finally loaded, in which case we simply ignore it.
-                        if (!pageUrl.equals(mUrl)) {
-                            return;
-                        }
+    public synchronized void updateFaviconURL(String faviconUrl, int size) {
+        // If we already have an "any" sized icon, don't update the icon.
+        if (mFaviconSize == -1)
+            return;
 
-                        // That one failed. Try the next one.
-                        if (favicon == null) {
-                            // If what we just tried to load originated from the set of declared icons..
-                            if (!mAvailableFavicons.isEmpty()) {
-                                // Discard it.
-                                mAvailableFavicons.remove(mAvailableFavicons.first());
-
-                                // Load the next best, if we have one. If not, it'll fall back to the
-                                // default Favicon URL, before giving up.
-                                loadFavicon();
-
-                                return;
-                            }
-
-                            // Total failure: display the default favicon.
-                            favicon = Favicons.defaultFavicon;
-                        }
-
-                        mFavicon = favicon;
-                        mFaviconLoadId = Favicons.NOT_LOADING;
-                        Tabs.getInstance().notifyListeners(Tab.this, Tabs.TabEvents.FAVICON);
-                    }
-                }
-        );
+        // Only update the favicon if it's bigger than the current favicon.
+        // We use -1 to represent icons with sizes="any".
+        if (size == -1 || size >= mFaviconSize) {
+            mFaviconUrl = faviconUrl;
+            mFaviconSize = size;
+        }
     }
 
     public synchronized void clearFavicon() {
-        // Cancel any ongoing favicon load (if we never finished downloading the old favicon before
-        // we changed page).
-        Favicons.cancelFaviconLoad(mFaviconLoadId);
-
         // Keep the favicon unchanged while entering reader mode
         if (mEnteringReaderMode)
             return;
 
         mFavicon = null;
         mFaviconUrl = null;
-        mAvailableFavicons.clear();
+        mFaviconSize = 0;
     }
 
     public void setHasFeeds(boolean hasFeeds) {
diff --git a/mobile/android/base/Tabs.java b/mobile/android/base/Tabs.java
index fbac0b21200e..2e15a122ac11 100644
--- a/mobile/android/base/Tabs.java
+++ b/mobile/android/base/Tabs.java
@@ -11,7 +11,6 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import android.graphics.Bitmap;
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ -30,6 +29,7 @@ import android.accounts.OnAccountsUpdateListener;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.database.ContentObserver;
+import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.net.Uri;
 import android.os.Handler;
@@ -505,20 +505,8 @@ public class Tabs implements GeckoEventListener {
             } else if (event.equals("DOMTitleChanged")) {
                 tab.updateTitle(message.getString("title"));
             } else if (event.equals("Link:Favicon")) {
-                // Don't bother if the type isn't one we can decode.
-                if (!Favicons.canDecodeType(message.getString("mime"))) {
-                    return;
-                }
-
-                // Add the favicon to the set of available icons for this tab.
-                tab.addFavicon(message.getString("href"), message.getInt("size"), message.getString("mime"));
-
-                // Load the favicon. If the tab is still loading, we actually do the load once the
-                // page has loaded, in an attempt to prevent the favicon load from having a
-                // detrimental effect on page load time.
-                if (tab.getState() != Tab.STATE_LOADING) {
-                    tab.loadFavicon();
-                }
+                tab.updateFaviconURL(message.getString("href"), message.getInt("size"));
+                notifyListeners(tab, TabEvents.LINK_FAVICON);
             } else if (event.equals("Link:Feed")) {
                 tab.setHasFeeds(true);
                 notifyListeners(tab, TabEvents.LINK_FEED);
@@ -547,6 +535,24 @@ public class Tabs implements GeckoEventListener {
         }
     }
 
+    /**
+     * Set the favicon for any tabs loaded with this page URL.
+     */
+    public void updateFaviconForURL(String pageURL, Bitmap favicon) {
+        // The tab might be pointing to another URL by the time the
+        // favicon is finally loaded, in which case we won't find the tab.
+        // See also: Bug 920331.
+        for (Tab tab : mOrder) {
+            String tabURL = tab.getURL();
+            if (pageURL.equals(tabURL)) {
+                tab.setFaviconLoadId(Favicons.NOT_LOADING);
+                if (tab.updateFavicon(favicon)) {
+                    notifyListeners(tab, TabEvents.FAVICON);
+                }
+            }
+        }
+    }
+
     public void refreshThumbnails() {
         final ThumbnailHelper helper = ThumbnailHelper.getInstance();
         ThreadUtils.postToBackgroundThread(new Runnable() {
@@ -589,6 +595,7 @@ public class Tabs implements GeckoEventListener {
         LOCATION_CHANGE,
         MENU_UPDATED,
         PAGE_SHOW,
+        LINK_FAVICON,
         LINK_FEED,
         SECURITY_CHANGE,
         READER_ENABLED,
@@ -832,8 +839,7 @@ public class Tabs implements GeckoEventListener {
         // TODO: surely we could just fetch *any* cached icon?
         if (AboutPages.isBuiltinIconPage(url)) {
             Log.d(LOGTAG, "Setting about: tab favicon inline.");
-            added.addFavicon(url, Favicons.browserToolbarFaviconSize, "");
-            added.loadFavicon();
+            added.updateFavicon(getAboutPageFavicon(url));
         }
 
         return added;
@@ -847,6 +853,17 @@ public class Tabs implements GeckoEventListener {
         return loadUrl(AboutPages.PRIVATEBROWSING, Tabs.LOADURL_NEW_TAB | Tabs.LOADURL_PRIVATE);
     }
 
+    /**
+     * These favicons are only used for the URL bar, so
+     * we fetch with that size.
+     *
+     * This method completes on the calling thread.
+     */
+    private Bitmap getAboutPageFavicon(final String url) {
+        int faviconSize = Math.round(mAppContext.getResources().getDimension(R.dimen.browser_toolbar_favicon_size));
+        return Favicons.getSizedFaviconForPageFromCache(url, faviconSize);
+    }
+
     /**
      * Open the url as a new tab, and mark the selected tab as its "parent".
      *
diff --git a/mobile/android/base/favicons/Favicons.java b/mobile/android/base/favicons/Favicons.java
index 6d83d871819a..2d3bf1b2013d 100644
--- a/mobile/android/base/favicons/Favicons.java
+++ b/mobile/android/base/favicons/Favicons.java
@@ -32,7 +32,6 @@ import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.concurrent.ExecutorService;
@@ -66,9 +65,6 @@ public class Favicons {
     // The density-adjusted maximum Favicon dimensions.
     public static int largestFaviconSize;
 
-    // The density-adjusted desired size for a browser-toolbar favicon.
-    public static int browserToolbarFaviconSize;
-
     // Used to prevent multiple-initialisation.
     public static final AtomicBoolean isInitialized = new AtomicBoolean(false);
 
@@ -81,57 +77,6 @@ public class Favicons {
     // doing so is not necessary.
     private static final NonEvictingLruCache<String, String> pageURLMappings = new NonEvictingLruCache<>(NUM_PAGE_URL_MAPPINGS_TO_STORE);
 
-    // Mime types of things we are capable of decoding.
-    private static final HashSet<String> sDecodableMimeTypes = new HashSet<>();
-
-    // Mime types of things we are both capable of decoding and are container formats (May contain
-    // multiple different sizes of image)
-    private static final HashSet<String> sContainerMimeTypes = new HashSet<>();
-    static {
-        // MIME types extracted from http://filext.com - ostensibly all in-use mime types for the
-        // corresponding formats.
-        // ICO
-        sContainerMimeTypes.add("image/vnd.microsoft.icon");
-        sContainerMimeTypes.add("image/ico");
-        sContainerMimeTypes.add("image/icon");
-        sContainerMimeTypes.add("image/x-icon");
-        sContainerMimeTypes.add("text/ico");
-        sContainerMimeTypes.add("application/ico");
-
-        // Add supported container types to the set of supported types.
-        sDecodableMimeTypes.addAll(sContainerMimeTypes);
-
-        // PNG
-        sDecodableMimeTypes.add("image/png");
-        sDecodableMimeTypes.add("application/png");
-        sDecodableMimeTypes.add("application/x-png");
-
-        // GIF
-        sDecodableMimeTypes.add("image/gif");
-
-        // JPEG
-        sDecodableMimeTypes.add("image/jpeg");
-        sDecodableMimeTypes.add("image/jpg");
-        sDecodableMimeTypes.add("image/pipeg");
-        sDecodableMimeTypes.add("image/vnd.swiftview-jpeg");
-        sDecodableMimeTypes.add("application/jpg");
-        sDecodableMimeTypes.add("application/x-jpg");
-
-        // BMP
-        sDecodableMimeTypes.add("application/bmp");
-        sDecodableMimeTypes.add("application/x-bmp");
-        sDecodableMimeTypes.add("application/x-win-bitmap");
-        sDecodableMimeTypes.add("image/bmp");
-        sDecodableMimeTypes.add("image/x-bmp");
-        sDecodableMimeTypes.add("image/x-bitmap");
-        sDecodableMimeTypes.add("image/x-xbitmap");
-        sDecodableMimeTypes.add("image/x-win-bitmap");
-        sDecodableMimeTypes.add("image/x-windows-bitmap");
-        sDecodableMimeTypes.add("image/x-ms-bitmap");
-        sDecodableMimeTypes.add("image/x-ms-bmp");
-        sDecodableMimeTypes.add("image/ms-bmp");
-    }
-
     public static String getFaviconURLForPageURLFromCache(String pageURL) {
         return pageURLMappings.get(pageURL);
     }
@@ -304,14 +249,9 @@ public class Favicons {
      *         or a somewhat educated guess.
      */
     public static String getFaviconURLForPageURL(Context context, String pageURL) {
-        // Query the URL cache.
-        String targetURL = getFaviconURLForPageURLFromCache(pageURL);
-        if (targetURL != null) {
-            return targetURL;
-        }
-
         // Attempt to determine the Favicon URL from the Tabs datastructure. Can dodge having to use
         // the database sometimes by doing this.
+        String targetURL;
         Tab theTab = Tabs.getInstance().getFirstTabForUrl(pageURL);
         if (theTab != null) {
             targetURL = theTab.getFaviconURL();
@@ -324,7 +264,6 @@ public class Favicons {
         final ContentResolver resolver = context.getContentResolver();
         targetURL = BrowserDB.getFaviconURLFromPageURL(resolver, pageURL);
         if (targetURL != null) {
-            putFaviconURLForPageURLInCache(pageURL, targetURL);
             return targetURL;
         }
 
@@ -477,7 +416,6 @@ public class Favicons {
         // TODO: Remove this branch when old tablet is removed.
         final int browserToolbarFaviconSizeDimenID = NewTabletUI.isEnabled(context) ?
                 R.dimen.new_tablet_tab_strip_favicon_size : R.dimen.browser_toolbar_favicon_size;
-        browserToolbarFaviconSize = res.getDimensionPixelSize(browserToolbarFaviconSizeDimenID);
 
         faviconsCache = new FaviconCache(FAVICON_CACHE_SIZE_BYTES, largestFaviconSize);
 
@@ -546,25 +484,6 @@ public class Favicons {
         }
     }
 
-    /**
-     * Helper function to determine if we can decode a particular mime type.
-     * @param imgType Mime type to check for decodability.
-     * @return false if the given mime type is certainly not decodable, true if it might be.
-     */
-    public static boolean canDecodeType(String imgType) {
-        return "".equals(imgType) || sDecodableMimeTypes.contains(imgType);
-    }
-
-    /**
-     * Helper function to determine if the provided mime type is that of a format that can contain
-     * multiple image types. At time of writing, the only such type is ICO.
-     * @param mimeType Mime type to check.
-     * @return true if the given mime type is a container type, false otherwise.
-     */
-    public static boolean isContainerType(String mimeType) {
-        return sDecodableMimeTypes.contains(mimeType);
-    }
-
     public static void removeLoadTask(int taskId) {
         synchronized(loadTasks) {
             loadTasks.delete(taskId);
diff --git a/mobile/android/base/favicons/LoadFaviconTask.java b/mobile/android/base/favicons/LoadFaviconTask.java
index caef1af24a75..596a1ddcb1f3 100644
--- a/mobile/android/base/favicons/LoadFaviconTask.java
+++ b/mobile/android/base/favicons/LoadFaviconTask.java
@@ -343,14 +343,36 @@ public class LoadFaviconTask {
             return pushToCacheAndGetResult(uriBitmaps);
         }
 
-        // Attempt to get a favicon URL from somewhere if we weren't given one...
-        if (TextUtils.isEmpty(faviconURL)) {
-            faviconURL = Favicons.getFaviconURLForPageURL(context, pageUrl);
-        }
+        String storedFaviconUrl;
+        boolean isUsingDefaultURL = false;
 
-        // We failed. Can't continue without a favicon URL!
+        // Handle the case of malformed favicon URL.
+        // If favicon is empty, fall back to the stored one.
         if (TextUtils.isEmpty(faviconURL)) {
-            return null;
+            // Try to get the favicon URL from the memory cache.
+            storedFaviconUrl = Favicons.getFaviconURLForPageURLFromCache(pageUrl);
+
+            // If that failed, try to get the URL from the database.
+            if (storedFaviconUrl == null) {
+                storedFaviconUrl = Favicons.getFaviconURLForPageURL(context, pageUrl);
+                if (storedFaviconUrl != null) {
+                    // If that succeeded, cache the URL loaded from the database in memory.
+                    Favicons.putFaviconURLForPageURLInCache(pageUrl, storedFaviconUrl);
+                }
+            }
+
+            // If we found a faviconURL - use it.
+            if (storedFaviconUrl != null) {
+                faviconURL = storedFaviconUrl;
+            } else {
+                // If we don't have a stored one, fall back to the default.
+                faviconURL = Favicons.guessDefaultFaviconURL(pageUrl);
+
+                if (TextUtils.isEmpty(faviconURL)) {
+                    return null;
+                }
+                isUsingDefaultURL = true;
+            }
         }
 
         // Check if favicon has failed - if so, give up. We need this check because, sometimes, we
@@ -422,13 +444,18 @@ public class LoadFaviconTask {
             return pushToCacheAndGetResult(loadedBitmaps);
         }
 
+        if (isUsingDefaultURL) {
+            Favicons.putFaviconInFailedCache(faviconURL);
+            return null;
+        }
+
         if (isCancelled()) {
             return null;
         }
 
         // If we're not already trying the default URL, try it now.
         final String guessed = Favicons.guessDefaultFaviconURL(pageUrl);
-        if (guessed == null || guessed.equals(faviconURL)) {
+        if (guessed == null) {
             Favicons.putFaviconInFailedCache(faviconURL);
             return null;
         }
diff --git a/mobile/android/base/favicons/RemoteFavicon.java b/mobile/android/base/favicons/RemoteFavicon.java
deleted file mode 100644
index 978a2a5862ce..000000000000
--- a/mobile/android/base/favicons/RemoteFavicon.java
+++ /dev/null
@@ -1,89 +0,0 @@
-/* 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/. */
-
-package org.mozilla.gecko.favicons;
-
-/**
- * Class to represent a Favicon declared on a webpage which we may or may not have downloaded.
- * Tab objects maintain a list of these and attempt to load them in descending order of quality
- * until one works. This enables us to fallback if something fails trying to decode a Favicon.
- */
-public class RemoteFavicon implements Comparable<RemoteFavicon> {
-    public static final int FAVICON_SIZE_ANY = -1;
-
-    // URL of the Favicon referred to by this object.
-    public String faviconUrl;
-
-    // The size of the Favicon, as given in the <link> tag, if any. Zero if unspecified. -1 if "any".
-    public int declaredSize;
-
-    // Mime type of the Favicon, as given in the link tag.
-    public String mimeType;
-
-    public RemoteFavicon(String faviconURL, int givenSize, String mime) {
-        faviconUrl = faviconURL;
-        declaredSize = givenSize;
-        mimeType = mime;
-    }
-
-    /**
-     * Determine equality of two RemoteFavicons.
-     * Two RemoteFavicons are considered equal if they have the same URL, size, and mime type.
-     * @param o The object to compare to this one.
-     * @return true if o is of type RemoteFavicon and is considered equal to this one, false otherwise.
-     */
-    @Override
-    public boolean equals(Object o) {
-        if (!(o instanceof RemoteFavicon)) {
-            return false;
-        }
-        RemoteFavicon oCast = (RemoteFavicon) o;
-
-        return oCast.faviconUrl.equals(faviconUrl) &&
-               oCast.declaredSize == declaredSize &&
-               oCast.mimeType.equals(mimeType);
-    }
-
-    @Override
-    public int hashCode() {
-        return super.hashCode();
-    }
-
-    /**
-     * Establish ordering on Favicons. Lower value in the partial ordering is a "better" Favicon.
-     * @param obj Object to compare against.
-     * @return -1 if this Favicon is "better" than the other, zero if they are equivalent in quality,
-     *         based on the information here, 1 if the other appears "better" than this one.
-     */
-    @Override
-    public int compareTo(RemoteFavicon obj) {
-        // Size "any" trumps everything else.
-        if (declaredSize == FAVICON_SIZE_ANY) {
-            if (obj.declaredSize == FAVICON_SIZE_ANY) {
-                return 0;
-            }
-
-            return -1;
-        }
-
-        if (obj.declaredSize == FAVICON_SIZE_ANY) {
-            return 1;
-        }
-
-        // Unspecified sizes are "worse".
-        if (declaredSize > obj.declaredSize) {
-            return -1;
-        }
-
-        if (declaredSize == obj.declaredSize) {
-            // If there's no other way to choose, we prefer container types. They *might* contain
-            // an image larger than the size given in the <link> tag.
-            if (Favicons.isContainerType(mimeType)) {
-                return -1;
-            }
-            return 0;
-        }
-        return 1;
-    }
-}
diff --git a/mobile/android/base/favicons/decoders/FaviconDecoder.java b/mobile/android/base/favicons/decoders/FaviconDecoder.java
index a1a8e4c354ae..4bd0da212af0 100644
--- a/mobile/android/base/favicons/decoders/FaviconDecoder.java
+++ b/mobile/android/base/favicons/decoders/FaviconDecoder.java
@@ -151,6 +151,50 @@ public class FaviconDecoder {
         return decodeFavicon(buffer, 0, buffer.length);
     }
 
+    /**
+     * Returns the smallest bitmap in the icon represented by the provided
+     * data: URI that's larger than the desired width, or the largest if
+     * there is no larger icon.
+     *
+     * Returns null if no bitmap could be extracted.
+     *
+     * Bug 961600: we shouldn't be doing all of this work. The favicon cache
+     * should be used, and will give us the right size icon.
+     */
+    public static Bitmap getMostSuitableBitmapFromDataURI(String iconURI, int desiredWidth) {
+        LoadFaviconResult result = FaviconDecoder.decodeDataURI(iconURI);
+        if (result == null) {
+            // Nothing we can do.
+            Log.w(LOG_TAG, "Unable to decode icon URI.");
+            return null;
+        }
+
+        final Iterator<Bitmap> bitmaps = result.getBitmaps();
+        if (!bitmaps.hasNext()) {
+            Log.w(LOG_TAG, "No bitmaps in decoded icon.");
+            return null;
+        }
+
+        Bitmap bitmap = bitmaps.next();
+        if (!bitmaps.hasNext()) {
+            // We're done! There was only one, so this is as big as it gets.
+            return bitmap;
+        }
+
+        // Find a bitmap of the most suitable size.
+        int currentWidth = bitmap.getWidth();
+        while ((currentWidth < desiredWidth) &&
+               bitmaps.hasNext()) {
+            final Bitmap b = bitmaps.next();
+            if (b.getWidth() > currentWidth) {
+                currentWidth = b.getWidth();
+                bitmap = b;
+            }
+        }
+
+        return bitmap;
+    }
+
     /**
      * Iterator to hold a single bitmap.
      */
diff --git a/mobile/android/base/moz.build b/mobile/android/base/moz.build
index 3784b54128fe..702f37ad8327 100644
--- a/mobile/android/base/moz.build
+++ b/mobile/android/base/moz.build
@@ -177,7 +177,6 @@ gbjar.sources += [
     'favicons/Favicons.java',
     'favicons/LoadFaviconTask.java',
     'favicons/OnFaviconLoadedListener.java',
-    'favicons/RemoteFavicon.java',
     'FilePicker.java',
     'FilePickerResultHandler.java',
     'FindInPageBar.java',
diff --git a/mobile/android/base/preferences/SearchEnginePreference.java b/mobile/android/base/preferences/SearchEnginePreference.java
index bf0946a79f26..ce0fab15fd13 100644
--- a/mobile/android/base/preferences/SearchEnginePreference.java
+++ b/mobile/android/base/preferences/SearchEnginePreference.java
@@ -8,7 +8,6 @@ import org.json.JSONException;
 import org.json.JSONObject;
 import org.mozilla.gecko.R;
 import org.mozilla.gecko.favicons.Favicons;
-import org.mozilla.gecko.favicons.OnFaviconLoadedListener;
 import org.mozilla.gecko.favicons.decoders.FaviconDecoder;
 import org.mozilla.gecko.util.ThreadUtils;
 import org.mozilla.gecko.widget.FaviconView;
@@ -35,7 +34,6 @@ public class SearchEnginePreference extends CustomListPreference {
 
     // The bitmap backing the drawable above - needed separately for the FaviconView.
     private Bitmap mIconBitmap;
-    private final Object bitmapLock = new Object();
 
     private FaviconView mFaviconView;
 
@@ -57,16 +55,9 @@ public class SearchEnginePreference extends CustomListPreference {
     protected void onBindView(View view) {
         super.onBindView(view);
 
-        // We synchronise to avoid a race condition between this and the favicon loading callback in
-        // setSearchEngineFromJSON.
-        synchronized (bitmapLock) {
-            // Set the icon in the FaviconView.
-            mFaviconView = ((FaviconView) view.findViewById(R.id.search_engine_icon));
-
-            if (mIconBitmap != null) {
-                mFaviconView.updateAndScaleImage(mIconBitmap, getTitle().toString());
-            }
-        }
+        // Set the icon in the FaviconView.
+        mFaviconView = ((FaviconView) view.findViewById(R.id.search_engine_icon));
+        mFaviconView.updateAndScaleImage(mIconBitmap, getTitle().toString());
     }
 
     @Override
@@ -170,20 +161,9 @@ public class SearchEnginePreference extends CustomListPreference {
                 }
             }
 
-            Favicons.getSizedFavicon(getContext(), mIdentifier, iconURI, desiredWidth, 0,
-                new OnFaviconLoadedListener() {
-                    @Override
-                    public void onFaviconLoaded(String url, String faviconURL, Bitmap favicon) {
-                        synchronized (bitmapLock) {
-                            mIconBitmap = favicon;
+            // TODO: use the cache. Bug 961600.
+            mIconBitmap = FaviconDecoder.getMostSuitableBitmapFromDataURI(iconURI, desiredWidth);
 
-                            if (mFaviconView != null) {
-                                mFaviconView.updateAndScaleImage(mIconBitmap, getTitle().toString());
-                            }
-                        }
-                    }
-                }
-            );
         } catch (IllegalArgumentException e) {
             Log.e(LOGTAG, "IllegalArgumentException creating Bitmap. Most likely a zero-length bitmap.", e);
         } catch (NullPointerException e) {
diff --git a/mobile/android/base/toolbar/ToolbarDisplayLayout.java b/mobile/android/base/toolbar/ToolbarDisplayLayout.java
index f1e2286c408a..c189e9d2ff7f 100644
--- a/mobile/android/base/toolbar/ToolbarDisplayLayout.java
+++ b/mobile/android/base/toolbar/ToolbarDisplayLayout.java
@@ -19,7 +19,6 @@ import org.mozilla.gecko.SiteIdentity.SecurityMode;
 import org.mozilla.gecko.Tab;
 import org.mozilla.gecko.animation.PropertyAnimator;
 import org.mozilla.gecko.animation.ViewHelper;
-import org.mozilla.gecko.favicons.Favicons;
 import org.mozilla.gecko.toolbar.BrowserToolbarTabletBase.ForwardButtonAnimation;
 import org.mozilla.gecko.util.StringUtils;
 import org.mozilla.gecko.widget.ThemedLinearLayout;
@@ -179,7 +178,7 @@ public class ToolbarDisplayLayout extends ThemedLinearLayout
             if (Versions.feature16Plus) {
                 mFavicon.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_NO);
             }
-            mFaviconSize = Math.round(Favicons.browserToolbarFaviconSize);
+            mFaviconSize = Math.round(res.getDimension(R.dimen.browser_toolbar_favicon_size));
         }
 
         mSiteSecurityVisible = (mSiteSecurity.getVisibility() == View.VISIBLE);
diff --git a/mobile/android/chrome/content/browser.js b/mobile/android/chrome/content/browser.js
index 379aa4a5ad74..ccb0404fba02 100644
--- a/mobile/android/chrome/content/browser.js
+++ b/mobile/android/chrome/content/browser.js
@@ -3960,8 +3960,7 @@ Tab.prototype = {
             type: "Link:Favicon",
             tabID: this.id,
             href: resolveGeckoURI(target.href),
-            size: maxSize,
-            mime: target.getAttribute("type") || ""
+            size: maxSize
           };
           Messaging.sendRequest(json);
         } else if (list.indexOf("[alternate]") != -1 && aEvent.type == "DOMLinkAdded") {