Bug 1480319: Split favicon loading code out of ContentLinkHandler.jsm. r=Mossop
authorKris Maglione <maglione.k@gmail.com>
Wed, 01 Aug 2018 21:36:12 -0700
changeset 431846 5746fe67e2d252035ca8257bd36d6b40d80fde39
parent 431845 48b8084995b1390b1f7b2214846ba19e2a55b6b2
child 431847 a91ccbe2b3fd8b9303b034d7a6035de572495fd0
push id34451
push userebalazs@mozilla.com
push dateThu, 16 Aug 2018 09:25:15 +0000
treeherdermozilla-central@161817e6d127 [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewersMossop
bugs1480319
milestone63.0a1
first release with
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
last release without
nightly linux32
nightly linux64
nightly mac
nightly win32
nightly win64
Bug 1480319: Split favicon loading code out of ContentLinkHandler.jsm. r=Mossop MozReview-Commit-ID: KyP42P5FJRq
browser/actors/LinkHandlerChild.jsm
browser/actors/moz.build
browser/base/content/content.js
browser/base/content/test/performance/browser_startup_content.js
browser/components/nsBrowserGlue.js
browser/modules/ContentLinkHandler.jsm
browser/modules/FaviconLoader.jsm
browser/modules/moz.build
toolkit/components/extensions/test/mochitest/test_ext_webrequest_filter.html
rename from browser/modules/ContentLinkHandler.jsm
rename to browser/actors/LinkHandlerChild.jsm
--- a/browser/modules/ContentLinkHandler.jsm
+++ b/browser/actors/LinkHandlerChild.jsm
@@ -1,573 +1,94 @@
 /* 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/. */
 
 "use strict";
 
-const EXPORTED_SYMBOLS = ["ContentLinkHandler"];
+const EXPORTED_SYMBOLS = ["LinkHandlerChild"];
 
-ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
-
-XPCOMUtils.defineLazyGlobalGetters(this, ["Blob", "FileReader"]);
+ChromeUtils.import("resource://gre/modules/ActorChild.jsm");
 
 ChromeUtils.defineModuleGetter(this, "Feeds",
   "resource:///modules/Feeds.jsm");
-ChromeUtils.defineModuleGetter(this, "DeferredTask",
-  "resource://gre/modules/DeferredTask.jsm");
-ChromeUtils.defineModuleGetter(this, "PromiseUtils",
-  "resource://gre/modules/PromiseUtils.jsm");
-
-const BinaryInputStream = Components.Constructor("@mozilla.org/binaryinputstream;1",
-                                                 "nsIBinaryInputStream", "setInputStream");
-
-const SIZES_TELEMETRY_ENUM = {
-  NO_SIZES: 0,
-  ANY: 1,
-  DIMENSION: 2,
-  INVALID: 3,
-};
-
-const FAVICON_PARSING_TIMEOUT = 100;
-const FAVICON_RICH_ICON_MIN_WIDTH = 96;
-const PREFERRED_WIDTH = 16;
-
-// URL schemes that we don't want to load and convert to data URLs.
-const LOCAL_FAVICON_SCHEMES = [
-  "chrome",
-  "about",
-  "resource",
-  "data",
-];
-
-const MAX_FAVICON_EXPIRATION = 7 * 24 * 60 * 60 * 1000;
-
-const TYPE_ICO = "image/x-icon";
-const TYPE_SVG = "image/svg+xml";
-
-function promiseBlobAsDataURL(blob) {
-  return new Promise((resolve, reject) => {
-    let reader = new FileReader();
-    reader.addEventListener("load", () => resolve(reader.result));
-    reader.addEventListener("error", reject);
-    reader.readAsDataURL(blob);
-  });
-}
-
-function promiseBlobAsOctets(blob) {
-  return new Promise((resolve, reject) => {
-    let reader = new FileReader();
-    reader.addEventListener("load", () => {
-      resolve(Array.from(reader.result).map(c => c.charCodeAt(0)));
-    });
-    reader.addEventListener("error", reject);
-    reader.readAsBinaryString(blob);
-  });
-}
-
-class FaviconLoad {
-  constructor(iconInfo) {
-    this.buffers = [];
-    this.icon = iconInfo;
-
-    this.channel = Services.io.newChannelFromURI2(
-      iconInfo.iconUri,
-      iconInfo.node,
-      iconInfo.node.nodePrincipal,
-      iconInfo.node.nodePrincipal,
-      (Ci.nsILoadInfo.SEC_ALLOW_CROSS_ORIGIN_DATA_INHERITS |
-       Ci.nsILoadInfo.SEC_ALLOW_CHROME |
-       Ci.nsILoadInfo.SEC_DISALLOW_SCRIPT),
-      Ci.nsIContentPolicy.TYPE_INTERNAL_IMAGE_FAVICON);
-
-    this.channel.loadFlags |= Ci.nsIRequest.LOAD_BACKGROUND;
-    // Sometimes node is a document and sometimes it is an element. This is
-    // the easiest single way to get to the load group in both those cases.
-    this.channel.loadGroup = iconInfo.node.ownerGlobal.document.documentLoadGroup;
-    this.channel.notificationCallbacks = this;
-
-    if (Services.prefs.getBoolPref("network.http.tailing.enabled", true) &&
-        this.channel instanceof Ci.nsIClassOfService) {
-      this.channel.addClassFlags(Ci.nsIClassOfService.Tail | Ci.nsIClassOfService.Throttleable);
-    }
-  }
-
-  load() {
-    this._deferred = PromiseUtils.defer();
-    // Clear the channel reference when we succeed or fail.
-    this._deferred.promise.then(
-      () => this.channel = null,
-      () => this.channel = null
-    );
-
-    try {
-      this.channel.asyncOpen2(this);
-    } catch (e) {
-      this._deferred.reject(e);
-    }
-
-    return this._deferred.promise;
-  }
-
-  cancel() {
-    if (!this.channel) {
-      return;
-    }
-
-    this.channel.cancel(Cr.NS_BINDING_ABORTED);
-  }
-
-  onStartRequest(request, context) {
-  }
+ChromeUtils.defineModuleGetter(this, "FaviconLoader",
+  "resource:///modules/FaviconLoader.jsm");
 
-  onDataAvailable(request, context, inputStream, offset, count) {
-    let stream = new BinaryInputStream(inputStream);
-    let buffer = new ArrayBuffer(count);
-    stream.readArrayBuffer(buffer.byteLength, buffer);
-    this.buffers.push(new Uint8Array(buffer));
-  }
-
-  asyncOnChannelRedirect(oldChannel, newChannel, flags, callback) {
-    if (oldChannel == this.channel) {
-      this.channel = newChannel;
-    }
-
-    callback.onRedirectVerifyCallback(Cr.NS_OK);
-  }
-
-  async onStopRequest(request, context, statusCode) {
-    if (request != this.channel) {
-      // Indicates that a redirect has occurred. We don't care about the result
-      // of the original channel.
-      return;
-    }
-
-    if (!Components.isSuccessCode(statusCode)) {
-      if (statusCode == Cr.NS_BINDING_ABORTED) {
-        this._deferred.reject(Components.Exception(`Favicon load from ${this.icon.iconUri.spec} was cancelled.`, statusCode));
-      } else {
-        this._deferred.reject(Components.Exception(`Favicon at "${this.icon.iconUri.spec}" failed to load.`, statusCode));
-      }
-      return;
-    }
-
-    if (this.channel instanceof Ci.nsIHttpChannel) {
-      if (!this.channel.requestSucceeded) {
-        this._deferred.reject(Components.Exception(`Favicon at "${this.icon.iconUri.spec}" failed to load: ${this.channel.responseStatusText}.`, Cr.NS_ERROR_FAILURE));
-        return;
-      }
-    }
-
-    // Attempt to get an expiration time from the cache.  If this fails, we'll
-    // use this default.
-    let expiration = Date.now() + MAX_FAVICON_EXPIRATION;
-
-    // This stuff isn't available after onStopRequest returns (so don't start
-    // any async operations before this!).
-    if (this.channel instanceof Ci.nsICacheInfoChannel) {
-      try {
-        expiration = Math.min(this.channel.cacheTokenExpirationTime * 1000, expiration);
-      } catch (e) {
-        // Ignore failures to get the expiration time.
-      }
-    }
-
-    try {
-      let type = this.channel.contentType;
-      let blob = new Blob(this.buffers, { type });
+class LinkHandlerChild extends ActorChild {
+  constructor(mm) {
+    super(mm);
 
-      if (type != "image/svg+xml") {
-        let octets = await promiseBlobAsOctets(blob);
-        let sniffer = Cc["@mozilla.org/image/loader;1"].
-                      createInstance(Ci.nsIContentSniffer);
-        type = sniffer.getMIMETypeFromContent(this.channel, octets, octets.length);
-
-        if (!type) {
-          throw Components.Exception(`Favicon at "${this.icon.iconUri.spec}" did not match a known mimetype.`, Cr.NS_ERROR_FAILURE);
-        }
-
-        blob = blob.slice(0, blob.size, type);
-      }
-
-      let dataURL = await promiseBlobAsDataURL(blob);
-
-      this._deferred.resolve({
-        expiration,
-        dataURL,
-      });
-    } catch (e) {
-      this._deferred.reject(e);
-    }
-  }
-
-  getInterface(iid) {
-    if (iid.equals(Ci.nsIChannelEventSink)) {
-      return this;
-    }
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  }
-}
-
-/*
- * Extract the icon width from the size attribute. It also sends the telemetry
- * about the size type and size dimension info.
- *
- * @param {Array} aSizes An array of strings about size.
- * @return {Number} A width of the icon in pixel.
- */
-function extractIconSize(aSizes) {
-  let width = -1;
-  let sizesType;
-  const re = /^([1-9][0-9]*)x[1-9][0-9]*$/i;
-
-  if (aSizes.length) {
-    for (let size of aSizes) {
-      if (size.toLowerCase() == "any") {
-        sizesType = SIZES_TELEMETRY_ENUM.ANY;
-        break;
-      } else {
-        let values = re.exec(size);
-        if (values && values.length > 1) {
-          sizesType = SIZES_TELEMETRY_ENUM.DIMENSION;
-          width = parseInt(values[1]);
-          break;
-        } else {
-          sizesType = SIZES_TELEMETRY_ENUM.INVALID;
-          break;
-        }
-      }
-    }
-  } else {
-    sizesType = SIZES_TELEMETRY_ENUM.NO_SIZES;
+    this.seenTabIcon = false;
+    this._iconLoader = null;
   }
 
-  // Telemetry probes for measuring the sizes attribute
-  // usage and available dimensions.
-  Services.telemetry.getHistogramById("LINK_ICON_SIZES_ATTR_USAGE").add(sizesType);
-  if (width > 0)
-    Services.telemetry.getHistogramById("LINK_ICON_SIZES_ATTR_DIMENSION").add(width);
-
-  return width;
-}
-
-/*
- * Get link icon URI from a link dom node.
- *
- * @param {DOMNode} aLink A link dom node.
- * @return {nsIURI} A uri of the icon.
- */
-function getLinkIconURI(aLink) {
-  let targetDoc = aLink.ownerDocument;
-  let uri = Services.io.newURI(aLink.href, targetDoc.characterSet);
-  try {
-    uri = uri.mutate().setUserPass("").finalize();
-  } catch (e) {
-    // some URIs are immutable
-  }
-  return uri;
-}
-
-/**
- * Guess a type for an icon based on its declared type or file extension.
- */
-function guessType(icon) {
-  // No type with no icon
-  if (!icon) {
-    return "";
-  }
-
-  // Use the file extension to guess at a type we're interested in
-  if (!icon.type) {
-    let extension = icon.iconUri.filePath.split(".").pop();
-    switch (extension) {
-      case "ico":
-        return TYPE_ICO;
-      case "svg":
-        return TYPE_SVG;
+  get iconLoader() {
+    if (!this._iconLoader) {
+      this._iconLoader = new FaviconLoader(this.mm);
     }
-  }
-
-  // Fuzzily prefer the type or fall back to the declared type
-  return icon.type == "image/vnd.microsoft.icon" ? TYPE_ICO : icon.type || "";
-}
-
-/*
- * Selects the best rich icon and tab icon from a list of IconInfo objects.
- *
- * @param {Array} iconInfos A list of IconInfo objects.
- * @param {integer} preferredWidth The preferred width for tab icons.
- */
-function selectIcons(iconInfos, preferredWidth) {
-  if (iconInfos.length == 0) {
-    return {
-      richIcon: null,
-      tabIcon: null,
-    };
-  }
-
-  let preferredIcon;
-  let bestSizedIcon;
-  // Other links with the "icon" tag are the default icons
-  let defaultIcon;
-  // Rich icons are either apple-touch or fluid icons, or the ones of the
-  // dimension 96x96 or greater
-  let largestRichIcon;
-
-  for (let icon of iconInfos) {
-    if (!icon.isRichIcon) {
-      // First check for svg. If it's not available check for an icon with a
-      // size adapt to the current resolution. If both are not available, prefer
-      // ico files. When multiple icons are in the same set, the latest wins.
-      if (guessType(icon) == TYPE_SVG) {
-        preferredIcon = icon;
-      } else if (icon.width == preferredWidth && guessType(preferredIcon) != TYPE_SVG) {
-        preferredIcon = icon;
-      } else if (guessType(icon) == TYPE_ICO && (!preferredIcon || guessType(preferredIcon) == TYPE_ICO)) {
-        preferredIcon = icon;
-      }
-
-      // Check for an icon larger yet closest to preferredWidth, that can be
-      // downscaled efficiently.
-      if (icon.width >= preferredWidth &&
-          (!bestSizedIcon || bestSizedIcon.width >= icon.width)) {
-        bestSizedIcon = icon;
-      }
-    }
-
-    // Note that some sites use hi-res icons without specifying them as
-    // apple-touch or fluid icons.
-    if (icon.isRichIcon || icon.width >= FAVICON_RICH_ICON_MIN_WIDTH) {
-      if (!largestRichIcon || largestRichIcon.width < icon.width) {
-        largestRichIcon = icon;
-      }
-    } else {
-      defaultIcon = icon;
-    }
-  }
-
-  // Now set the favicons for the page in the following order:
-  // 1. Set the best rich icon if any.
-  // 2. Set the preferred one if any, otherwise check if there's a better
-  //    sized fit.
-  // This order allows smaller icon frames to eventually override rich icon
-  // frames.
-
-  let tabIcon = null;
-  if (preferredIcon) {
-    tabIcon = preferredIcon;
-  } else if (bestSizedIcon) {
-    tabIcon = bestSizedIcon;
-  } else if (defaultIcon) {
-    tabIcon = defaultIcon;
+    return this._iconLoader;
   }
 
-  return {
-    richIcon: largestRichIcon,
-    tabIcon
-  };
-}
-
-function makeFaviconFromLink(aLink, aIsRichIcon) {
-  let iconUri = getLinkIconURI(aLink);
-  if (!iconUri)
-    return null;
-
-  // Extract the size type and width.
-  let width = extractIconSize(aLink.sizes);
-
-  return {
-    iconUri,
-    width,
-    isRichIcon: aIsRichIcon,
-    type: aLink.type,
-    node: aLink,
-  };
-}
-
-class IconLoader {
-  constructor(chromeGlobal) {
-    this.chromeGlobal = chromeGlobal;
-  }
-
-  async load(iconInfo) {
-    if (this._loader) {
-      this._loader.cancel();
-    }
-
-    if (LOCAL_FAVICON_SCHEMES.includes(iconInfo.iconUri.scheme)) {
-      this.chromeGlobal.sendAsyncMessage("Link:SetIcon", {
-        originalURL: iconInfo.iconUri.spec,
-        canUseForTab: !iconInfo.isRichIcon,
-        expiration: undefined,
-        iconURL: iconInfo.iconUri.spec,
-      });
-      return;
-    }
-
-    try {
-      this._loader = new FaviconLoad(iconInfo);
-      let { dataURL, expiration } = await this._loader.load();
-
-      this.chromeGlobal.sendAsyncMessage("Link:SetIcon", {
-        originalURL: iconInfo.iconUri.spec,
-        canUseForTab: !iconInfo.isRichIcon,
-        expiration,
-        iconURL: dataURL,
-      });
-    } catch (e) {
-      if (e.resultCode != Cr.NS_BINDING_ABORTED) {
-        Cu.reportError(e);
-
-        // Used mainly for tests currently.
-        this.chromeGlobal.sendAsyncMessage("Link:SetFailedIcon", {
-          originalURL: iconInfo.iconUri.spec,
-          canUseForTab: !iconInfo.isRichIcon,
-        });
+  addRootIcon() {
+    if (!this.seenTabIcon && Services.prefs.getBoolPref("browser.chrome.guess_favicon", true) &&
+        Services.prefs.getBoolPref("browser.chrome.site_icons", true)) {
+      // Inject the default icon. Use documentURIObject so that we do the right
+      // thing with about:-style error pages. See bug 453442
+      let baseURI = this.content.document.documentURIObject;
+      if (["http", "https"].includes(baseURI.scheme)) {
+        this.seenTabIcon = true;
+        this.iconLoader.addDefaultIcon(baseURI);
       }
-    } finally {
-      this._loader = null;
-    }
-  }
-
-  cancel() {
-    if (!this._loader) {
-      return;
-    }
-
-    this._loader.cancel();
-    this._loader = null;
-  }
-}
-
-class ContentLinkHandler {
-  constructor(chromeGlobal) {
-    this.chromeGlobal = chromeGlobal;
-    this.iconInfos = [];
-    this.seenTabIcon = false;
-
-    chromeGlobal.addEventListener("DOMLinkAdded", this);
-    chromeGlobal.addEventListener("DOMLinkChanged", this);
-    chromeGlobal.addEventListener("pageshow", this);
-    chromeGlobal.addEventListener("pagehide", this);
-    chromeGlobal.addEventListener("DOMHeadElementParsed", this);
-
-    // For every page we attempt to find a rich icon and a tab icon. These
-    // objects take care of the load process for each.
-    this.richIconLoader = new IconLoader(chromeGlobal);
-    this.tabIconLoader = new IconLoader(chromeGlobal);
-
-    this.iconTask = new DeferredTask(() => this.loadIcons(), FAVICON_PARSING_TIMEOUT);
-  }
-
-  loadIcons() {
-    let preferredWidth = PREFERRED_WIDTH * Math.ceil(this.chromeGlobal.content.devicePixelRatio);
-    let { richIcon, tabIcon } = selectIcons(this.iconInfos, preferredWidth);
-    this.iconInfos = [];
-
-    if (richIcon) {
-      this.richIconLoader.load(richIcon);
-    }
-
-    if (tabIcon) {
-      this.tabIconLoader.load(tabIcon);
-    }
-  }
-
-  addIcon(iconInfo) {
-    if (!Services.prefs.getBoolPref("browser.chrome.site_icons", true)) {
-      return;
-    }
-
-    if (!iconInfo.isRichIcon) {
-      this.seenTabIcon = true;
-    }
-    this.iconInfos.push(iconInfo);
-    this.iconTask.arm();
-  }
-
-  addRootIcon(document) {
-    // If we've already seen a tab icon or if root favicons are disabled then
-    // bail out.
-    if (this.seenTabIcon || !Services.prefs.getBoolPref("browser.chrome.guess_favicon", true)) {
-      return;
-    }
-
-    // Currently ImageDocuments will just load the default favicon, see bug
-    // 403651 for discussion.
-
-    // Inject the default icon. Use documentURIObject so that we do the right
-    // thing with about:-style error pages. See bug 453442
-    let baseURI = document.documentURIObject;
-    if (baseURI.schemeIs("http") || baseURI.schemeIs("https")) {
-      let iconUri = baseURI.mutate().setPathQueryRef("/favicon.ico").finalize();
-      this.addIcon({
-        iconUri,
-        width: -1,
-        isRichIcon: false,
-        type: TYPE_ICO,
-        node: document,
-      });
     }
   }
 
   onHeadParsed(event) {
-    let document = this.chromeGlobal.content.document;
-    if (event.target.ownerDocument != document) {
+    if (event.target.ownerDocument != this.content.document) {
       return;
     }
 
     // Per spec icons are meant to be in the <head> tag so we should have seen
     // all the icons now so add the root icon if no other tab icons have been
     // seen.
-    this.addRootIcon(document);
+    this.addRootIcon();
 
     // We're likely done with icon parsing so load the pending icons now.
-    if (this.iconTask.isArmed) {
-      this.iconTask.disarm();
-      this.loadIcons();
+    if (this._iconLoader) {
+      this._iconLoader.onPageShow();
     }
   }
 
   onPageShow(event) {
-    let document = this.chromeGlobal.content.document;
-    if (event.target != document) {
+    if (event.target != this.content.document) {
       return;
     }
 
-    // Add the root icon if it hasn't already been added. We encounter this case
-    // for documents that do not have a <head> tag.
-    this.addRootIcon(document);
+    this.addRootIcon();
 
-    // If we've seen any additional icons since the start of the body element
-    // load them now.
-    if (this.iconTask.isArmed) {
-      this.iconTask.disarm();
-      this.loadIcons();
+    if (this._iconLoader) {
+      this._iconLoader.onPageShow();
     }
   }
 
   onPageHide(event) {
-    if (event.target != this.chromeGlobal.content.document) {
+    if (event.target != this.content.document) {
       return;
     }
 
-    this.richIconLoader.cancel();
-    this.tabIconLoader.cancel();
-
-    this.iconTask.disarm();
-    this.iconInfos = [];
-    this.seenTabIcon = false;
+    if (this._iconLoader) {
+      this._iconLoader.onPageHide();
+    }
   }
 
   onLinkEvent(event) {
     let link = event.target;
     // Ignore sub-frames (bugs 305472, 479408).
-    if (link.ownerGlobal != this.chromeGlobal.content) {
+    if (link.ownerGlobal != this.content) {
       return;
     }
 
     let rel = link.rel && link.rel.toLowerCase();
     if (!rel || !link.href)
       return;
 
     // Note: following booleans only work for the current link, not for the
@@ -575,83 +96,87 @@ class ContentLinkHandler {
     let feedAdded = false;
     let iconAdded = false;
     let searchAdded = false;
     let rels = {};
     for (let relString of rel.split(/\s+/))
       rels[relString] = true;
 
     for (let relVal in rels) {
-      let isRichIcon = true;
+      let isRichIcon = false;
 
       switch (relVal) {
         case "feed":
         case "alternate":
           if (!feedAdded && event.type == "DOMLinkAdded") {
             if (!rels.feed && rels.alternate && rels.stylesheet)
               break;
 
             if (Feeds.isValidFeed(link, link.ownerDocument.nodePrincipal, "feed" in rels)) {
-              this.chromeGlobal.sendAsyncMessage("Link:AddFeed", {
+              this.mm.sendAsyncMessage("Link:AddFeed", {
                 type: link.type,
                 href: link.href,
                 title: link.title,
               });
               feedAdded = true;
             }
           }
           break;
-        case "icon":
-          isRichIcon = false;
-          // Fall through to rich icon handling
         case "apple-touch-icon":
         case "apple-touch-icon-precomposed":
         case "fluid-icon":
+          isRichIcon = true;
+        case "icon":
           if (iconAdded || link.hasAttribute("mask")) { // Masked icons are not supported yet.
             break;
           }
 
-          let iconInfo = makeFaviconFromLink(link, isRichIcon);
+          if (!Services.prefs.getBoolPref("browser.chrome.site_icons", true)) {
+            return;
+          }
+
+          let iconInfo = FaviconLoader.makeFaviconFromLink(link, isRichIcon);
           if (iconInfo) {
-            iconAdded = this.addIcon(iconInfo);
+            iconAdded = true;
+            if (!isRichIcon) {
+              this.seenTabIcon = true;
+            }
+            this.iconLoader.addIcon(iconInfo);
           }
           break;
         case "search":
           if (Services.policies && !Services.policies.isAllowed("installSearchEngine")) {
             break;
           }
 
           if (!searchAdded && event.type == "DOMLinkAdded") {
             let type = link.type && link.type.toLowerCase();
             type = type.replace(/^\s+|\s*(?:;.*)?$/g, "");
 
             let re = /^(?:https?|ftp):/i;
             if (type == "application/opensearchdescription+xml" && link.title &&
                 re.test(link.href)) {
               let engine = { title: link.title, href: link.href };
-              this.chromeGlobal.sendAsyncMessage("Link:AddSearch", {
+              this.mm.sendAsyncMessage("Link:AddSearch", {
                 engine,
                 url: link.ownerDocument.documentURI,
               });
               searchAdded = true;
             }
           }
           break;
       }
     }
   }
 
   handleEvent(event) {
     switch (event.type) {
       case "pageshow":
-        this.onPageShow(event);
-        break;
+        return this.onPageShow(event);
       case "pagehide":
-        this.onPageHide(event);
-        break;
+        return this.onPageHide(event);
       case "DOMHeadElementParsed":
-        this.onHeadParsed(event);
-        break;
+        return this.onHeadParsed(event);
       default:
-        this.onLinkEvent(event);
+        return this.onLinkEvent(event);
     }
   }
 }
--- a/browser/actors/moz.build
+++ b/browser/actors/moz.build
@@ -26,16 +26,17 @@ FINAL_TARGET_FILES.actors += [
     'AboutReaderChild.jsm',
     'BlockedSiteChild.jsm',
     'BrowserTabChild.jsm',
     'ClickHandlerChild.jsm',
     'ContentSearchChild.jsm',
     'ContextMenuChild.jsm',
     'DOMFullscreenChild.jsm',
     'LightWeightThemeInstallChild.jsm',
+    'LinkHandlerChild.jsm',
     'NetErrorChild.jsm',
     'OfflineAppsChild.jsm',
     'PageInfoChild.jsm',
     'PageMetadataChild.jsm',
     'PageStyleChild.jsm',
     'PluginChild.jsm',
     'URIFixupChild.jsm',
     'WebRTCChild.jsm',
--- a/browser/base/content/content.js
+++ b/browser/base/content/content.js
@@ -11,17 +11,16 @@
 
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 // TabChildGlobal
 var global = this;
 
 XPCOMUtils.defineLazyModuleGetters(this, {
-  ContentLinkHandler: "resource:///modules/ContentLinkHandler.jsm",
   ContentMetaHandler: "resource:///modules/ContentMetaHandler.jsm",
   LoginFormFactory: "resource://gre/modules/LoginManagerContent.jsm",
   InsecurePasswordUtils: "resource://gre/modules/InsecurePasswordUtils.jsm",
   FormSubmitObserver: "resource:///modules/FormSubmitObserver.jsm",
   ContextMenuChild: "resource:///actors/ContextMenuChild.jsm",
 });
 
 XPCOMUtils.defineLazyGetter(this, "LoginManagerContent", () => {
@@ -55,17 +54,16 @@ addEventListener("DOMInputPasswordAdded"
   LoginManagerContent.onDOMInputPasswordAdded(event, content);
   let formLike = LoginFormFactory.createFromField(event.originalTarget);
   InsecurePasswordUtils.reportInsecurePasswords(formLike);
 });
 addEventListener("DOMAutoComplete", function(event) {
   LoginManagerContent.onUsernameInput(event);
 });
 
-new ContentLinkHandler(this);
 ContentMetaHandler.init(this);
 
 // This is a temporary hack to prevent regressions (bug 1471327).
 void content;
 
 addEventListener("DOMWindowFocus", function(event) {
   sendAsyncMessage("DOMWindowFocus", {});
 }, false);
--- a/browser/base/content/test/performance/browser_startup_content.js
+++ b/browser/base/content/test/performance/browser_startup_content.js
@@ -45,18 +45,18 @@ const whitelist = {
 
     // Forms and passwords
     "resource://formautofill/FormAutofill.jsm",
     "resource://formautofill/FormAutofillContent.jsm",
 
     // Browser front-end
     "resource:///actors/AboutReaderChild.jsm",
     "resource:///actors/BrowserTabChild.jsm",
-    "resource:///modules/ContentLinkHandler.jsm",
     "resource:///modules/ContentMetaHandler.jsm",
+    "resource:///actors/LinkHandlerChild.jsm",
     "resource:///actors/PageStyleChild.jsm",
     "resource://gre/modules/ActorChild.jsm",
     "resource://gre/modules/ActorManagerChild.jsm",
     "resource://gre/modules/E10SUtils.jsm",
     "resource://gre/modules/PrivateBrowsingUtils.jsm",
     "resource://gre/modules/ReaderMode.jsm",
     "resource://gre/modules/WebProgressChild.jsm",
 
--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -126,16 +126,29 @@ let ACTORS = {
       events: {
         "InstallBrowserTheme": {wantUntrusted: true},
         "PreviewBrowserTheme": {wantUntrusted: true},
         "ResetBrowserThemePreview": {wantUntrusted: true},
       },
     },
   },
 
+  LinkHandler: {
+    child: {
+      module: "resource:///actors/LinkHandlerChild.jsm",
+      events: {
+        "DOMHeadElementParsed": {},
+        "DOMLinkAdded": {},
+        "DOMLinkChanged": {},
+        "pageshow": {},
+        "pagehide": {},
+      },
+    },
+  },
+
   NetError: {
     child: {
       module: "resource:///actors/NetErrorChild.jsm",
       events: {
         "AboutNetErrorLoad": {wantUntrusted: true},
         "AboutNetErrorOpenCaptivePortal": {wantUntrusted: true},
         "AboutNetErrorSetAutomatic": {wantUntrusted: true},
         "AboutNetErrorResetPreferences": {wantUntrusted: true},
copy from browser/modules/ContentLinkHandler.jsm
copy to browser/modules/FaviconLoader.jsm
--- a/browser/modules/ContentLinkHandler.jsm
+++ b/browser/modules/FaviconLoader.jsm
@@ -1,23 +1,21 @@
 /* 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/. */
 
 "use strict";
 
-const EXPORTED_SYMBOLS = ["ContentLinkHandler"];
+const EXPORTED_SYMBOLS = ["FaviconLoader"];
 
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 XPCOMUtils.defineLazyGlobalGetters(this, ["Blob", "FileReader"]);
 
-ChromeUtils.defineModuleGetter(this, "Feeds",
-  "resource:///modules/Feeds.jsm");
 ChromeUtils.defineModuleGetter(this, "DeferredTask",
   "resource://gre/modules/DeferredTask.jsm");
 ChromeUtils.defineModuleGetter(this, "PromiseUtils",
   "resource://gre/modules/PromiseUtils.jsm");
 
 const BinaryInputStream = Components.Constructor("@mozilla.org/binaryinputstream;1",
                                                  "nsIBinaryInputStream", "setInputStream");
 
@@ -362,69 +360,52 @@ function selectIcons(iconInfos, preferre
   }
 
   return {
     richIcon: largestRichIcon,
     tabIcon
   };
 }
 
-function makeFaviconFromLink(aLink, aIsRichIcon) {
-  let iconUri = getLinkIconURI(aLink);
-  if (!iconUri)
-    return null;
-
-  // Extract the size type and width.
-  let width = extractIconSize(aLink.sizes);
-
-  return {
-    iconUri,
-    width,
-    isRichIcon: aIsRichIcon,
-    type: aLink.type,
-    node: aLink,
-  };
-}
-
 class IconLoader {
-  constructor(chromeGlobal) {
-    this.chromeGlobal = chromeGlobal;
+  constructor(mm) {
+    this.mm = mm;
   }
 
   async load(iconInfo) {
     if (this._loader) {
       this._loader.cancel();
     }
 
     if (LOCAL_FAVICON_SCHEMES.includes(iconInfo.iconUri.scheme)) {
-      this.chromeGlobal.sendAsyncMessage("Link:SetIcon", {
+      this.mm.sendAsyncMessage("Link:SetIcon", {
         originalURL: iconInfo.iconUri.spec,
         canUseForTab: !iconInfo.isRichIcon,
         expiration: undefined,
         iconURL: iconInfo.iconUri.spec,
       });
       return;
     }
 
     try {
       this._loader = new FaviconLoad(iconInfo);
       let { dataURL, expiration } = await this._loader.load();
 
-      this.chromeGlobal.sendAsyncMessage("Link:SetIcon", {
+      this.mm.sendAsyncMessage("Link:SetIcon", {
         originalURL: iconInfo.iconUri.spec,
         canUseForTab: !iconInfo.isRichIcon,
         expiration,
         iconURL: dataURL,
       });
     } catch (e) {
-      if (e.resultCode != Cr.NS_BINDING_ABORTED) {
+      if (e.result != Cr.NS_BINDING_ABORTED) {
         Cu.reportError(e);
 
         // Used mainly for tests currently.
-        this.chromeGlobal.sendAsyncMessage("Link:SetFailedIcon", {
+        this.mm.sendAsyncMessage("Link:SetFailedIcon", {
           originalURL: iconInfo.iconUri.spec,
           canUseForTab: !iconInfo.isRichIcon,
         });
       }
     } finally {
       this._loader = null;
     }
   }
@@ -434,224 +415,85 @@ class IconLoader {
       return;
     }
 
     this._loader.cancel();
     this._loader = null;
   }
 }
 
-class ContentLinkHandler {
-  constructor(chromeGlobal) {
-    this.chromeGlobal = chromeGlobal;
+class FaviconLoader {
+  constructor(mm) {
+    this.mm = mm;
     this.iconInfos = [];
-    this.seenTabIcon = false;
-
-    chromeGlobal.addEventListener("DOMLinkAdded", this);
-    chromeGlobal.addEventListener("DOMLinkChanged", this);
-    chromeGlobal.addEventListener("pageshow", this);
-    chromeGlobal.addEventListener("pagehide", this);
-    chromeGlobal.addEventListener("DOMHeadElementParsed", this);
 
     // For every page we attempt to find a rich icon and a tab icon. These
     // objects take care of the load process for each.
-    this.richIconLoader = new IconLoader(chromeGlobal);
-    this.tabIconLoader = new IconLoader(chromeGlobal);
+    this.richIconLoader = new IconLoader(mm);
+    this.tabIconLoader = new IconLoader(mm);
 
     this.iconTask = new DeferredTask(() => this.loadIcons(), FAVICON_PARSING_TIMEOUT);
   }
 
   loadIcons() {
-    let preferredWidth = PREFERRED_WIDTH * Math.ceil(this.chromeGlobal.content.devicePixelRatio);
+    let preferredWidth = PREFERRED_WIDTH * Math.ceil(this.mm.content.devicePixelRatio);
     let { richIcon, tabIcon } = selectIcons(this.iconInfos, preferredWidth);
     this.iconInfos = [];
 
     if (richIcon) {
       this.richIconLoader.load(richIcon);
     }
 
     if (tabIcon) {
       this.tabIconLoader.load(tabIcon);
     }
   }
 
   addIcon(iconInfo) {
-    if (!Services.prefs.getBoolPref("browser.chrome.site_icons", true)) {
-      return;
-    }
-
-    if (!iconInfo.isRichIcon) {
-      this.seenTabIcon = true;
-    }
     this.iconInfos.push(iconInfo);
     this.iconTask.arm();
   }
 
-  addRootIcon(document) {
-    // If we've already seen a tab icon or if root favicons are disabled then
-    // bail out.
-    if (this.seenTabIcon || !Services.prefs.getBoolPref("browser.chrome.guess_favicon", true)) {
-      return;
-    }
-
+  addDefaultIcon(baseURI) {
     // Currently ImageDocuments will just load the default favicon, see bug
     // 403651 for discussion.
-
-    // Inject the default icon. Use documentURIObject so that we do the right
-    // thing with about:-style error pages. See bug 453442
-    let baseURI = document.documentURIObject;
-    if (baseURI.schemeIs("http") || baseURI.schemeIs("https")) {
-      let iconUri = baseURI.mutate().setPathQueryRef("/favicon.ico").finalize();
-      this.addIcon({
-        iconUri,
-        width: -1,
-        isRichIcon: false,
-        type: TYPE_ICO,
-        node: document,
-      });
-    }
+    this.addIcon({
+      iconUri: baseURI.mutate().setPathQueryRef("/favicon.ico").finalize(),
+      width: -1,
+      isRichIcon: false,
+      type: TYPE_ICO,
+      node: this.mm.content.document,
+    });
   }
 
-  onHeadParsed(event) {
-    let document = this.chromeGlobal.content.document;
-    if (event.target.ownerDocument != document) {
-      return;
-    }
-
-    // Per spec icons are meant to be in the <head> tag so we should have seen
-    // all the icons now so add the root icon if no other tab icons have been
-    // seen.
-    this.addRootIcon(document);
-
+  onPageShow() {
     // We're likely done with icon parsing so load the pending icons now.
     if (this.iconTask.isArmed) {
       this.iconTask.disarm();
       this.loadIcons();
     }
   }
 
-  onPageShow(event) {
-    let document = this.chromeGlobal.content.document;
-    if (event.target != document) {
-      return;
-    }
-
-    // Add the root icon if it hasn't already been added. We encounter this case
-    // for documents that do not have a <head> tag.
-    this.addRootIcon(document);
-
-    // If we've seen any additional icons since the start of the body element
-    // load them now.
-    if (this.iconTask.isArmed) {
-      this.iconTask.disarm();
-      this.loadIcons();
-    }
-  }
-
-  onPageHide(event) {
-    if (event.target != this.chromeGlobal.content.document) {
-      return;
-    }
-
+  onPageHide() {
     this.richIconLoader.cancel();
     this.tabIconLoader.cancel();
 
     this.iconTask.disarm();
     this.iconInfos = [];
-    this.seenTabIcon = false;
   }
 
-  onLinkEvent(event) {
-    let link = event.target;
-    // Ignore sub-frames (bugs 305472, 479408).
-    if (link.ownerGlobal != this.chromeGlobal.content) {
-      return;
-    }
-
-    let rel = link.rel && link.rel.toLowerCase();
-    if (!rel || !link.href)
-      return;
+  static makeFaviconFromLink(aLink, aIsRichIcon) {
+    let iconUri = getLinkIconURI(aLink);
+    if (!iconUri)
+      return null;
 
-    // Note: following booleans only work for the current link, not for the
-    // whole content
-    let feedAdded = false;
-    let iconAdded = false;
-    let searchAdded = false;
-    let rels = {};
-    for (let relString of rel.split(/\s+/))
-      rels[relString] = true;
-
-    for (let relVal in rels) {
-      let isRichIcon = true;
-
-      switch (relVal) {
-        case "feed":
-        case "alternate":
-          if (!feedAdded && event.type == "DOMLinkAdded") {
-            if (!rels.feed && rels.alternate && rels.stylesheet)
-              break;
+    // Extract the size type and width.
+    let width = extractIconSize(aLink.sizes);
 
-            if (Feeds.isValidFeed(link, link.ownerDocument.nodePrincipal, "feed" in rels)) {
-              this.chromeGlobal.sendAsyncMessage("Link:AddFeed", {
-                type: link.type,
-                href: link.href,
-                title: link.title,
-              });
-              feedAdded = true;
-            }
-          }
-          break;
-        case "icon":
-          isRichIcon = false;
-          // Fall through to rich icon handling
-        case "apple-touch-icon":
-        case "apple-touch-icon-precomposed":
-        case "fluid-icon":
-          if (iconAdded || link.hasAttribute("mask")) { // Masked icons are not supported yet.
-            break;
-          }
-
-          let iconInfo = makeFaviconFromLink(link, isRichIcon);
-          if (iconInfo) {
-            iconAdded = this.addIcon(iconInfo);
-          }
-          break;
-        case "search":
-          if (Services.policies && !Services.policies.isAllowed("installSearchEngine")) {
-            break;
-          }
-
-          if (!searchAdded && event.type == "DOMLinkAdded") {
-            let type = link.type && link.type.toLowerCase();
-            type = type.replace(/^\s+|\s*(?:;.*)?$/g, "");
-
-            let re = /^(?:https?|ftp):/i;
-            if (type == "application/opensearchdescription+xml" && link.title &&
-                re.test(link.href)) {
-              let engine = { title: link.title, href: link.href };
-              this.chromeGlobal.sendAsyncMessage("Link:AddSearch", {
-                engine,
-                url: link.ownerDocument.documentURI,
-              });
-              searchAdded = true;
-            }
-          }
-          break;
-      }
-    }
-  }
-
-  handleEvent(event) {
-    switch (event.type) {
-      case "pageshow":
-        this.onPageShow(event);
-        break;
-      case "pagehide":
-        this.onPageHide(event);
-        break;
-      case "DOMHeadElementParsed":
-        this.onHeadParsed(event);
-        break;
-      default:
-        this.onLinkEvent(event);
-    }
+    return {
+      iconUri,
+      width,
+      isRichIcon: aIsRichIcon,
+      type: aLink.type,
+      node: aLink,
+    };
   }
 }
--- a/browser/modules/moz.build
+++ b/browser/modules/moz.build
@@ -119,21 +119,21 @@ XPCSHELL_TESTS_MANIFESTS += ['test/unit/
 EXTRA_JS_MODULES += [
     'AboutNewTab.jsm',
     'AsyncTabSwitcher.jsm',
     'BrowserErrorReporter.jsm',
     'BrowserUsageTelemetry.jsm',
     'BrowserWindowTracker.jsm',
     'ContentClick.jsm',
     'ContentCrashHandlers.jsm',
-    'ContentLinkHandler.jsm',
     'ContentMetaHandler.jsm',
     'ContentObservers.js',
     'ContentSearch.jsm',
     'ExtensionsUI.jsm',
+    'FaviconLoader.jsm',
     'Feeds.jsm',
     'FormSubmitObserver.jsm',
     'FormValidationHandler.jsm',
     'HomePage.jsm',
     'LaterRun.jsm',
     'LightweightThemeChildHelper.jsm',
     'OpenInTabsUtils.jsm',
     'PageActions.jsm',
--- a/toolkit/components/extensions/test/mochitest/test_ext_webrequest_filter.html
+++ b/toolkit/components/extensions/test/mochitest/test_ext_webrequest_filter.html
@@ -131,24 +131,16 @@ add_task(async function test_webRequest_
     "file_image_good.png": {
       // These events only happen in non-e10s. See bug 1472156.
       optional_events: ["onBeforeRedirect", "onBeforeRequest", "onBeforeSendHeaders", "onSendHeaders"],
       type: "main_frame",
       // cached: AppConstants.MOZ_BUILD_APP === "browser",
     },
   };
 
-  if (AppConstants.platform != "android") {
-    expect["favicon.ico"] = {
-      optional_events: ["onBeforeRedirect", "onBeforeRequest", "onBeforeSendHeaders", "onSendHeaders"],
-      type: "image",
-      origin: SimpleTest.getTestFileURL(img),
-    };
-  }
-
   let extension = makeExtension(events);
   await extension.startup();
   extension.sendMessage("set-expected", {expect, origin: location.href});
   await extension.awaitMessage("continue");
 
   if (AppConstants.MOZ_BUILD_APP === "browser") {
     // We should not get events for a new window load.
     let newWindow = window.open(img, "_blank", "width=100,height=100");