--- a/toolkit/mozapps/extensions/AddonManager.jsm
+++ b/toolkit/mozapps/extensions/AddonManager.jsm
@@ -33,17 +33,16 @@ const PREF_APP_UPDATE_ENABLED         = 
 const PREF_APP_UPDATE_AUTO            = "app.update.auto";
 const UNKNOWN_XPCOM_ABI               = "unknownABI";
 
 const PREF_MIN_WEBEXT_PLATFORM_VERSION = "extensions.webExtensionsMinPlatformVersion";
 const PREF_WEBAPI_TESTING             = "extensions.webapi.testing";
 const PREF_WEBEXT_PERM_PROMPTS        = "extensions.webextPermissionPrompts";
 
 const UPDATE_REQUEST_VERSION          = 2;
-const CATEGORY_UPDATE_PARAMS          = "extension-update-params";
 
 const XMLURI_BLOCKLIST                = "http://www.mozilla.org/2006/addons-blocklist";
 
 const KEY_PROFILEDIR                  = "ProfD";
 const KEY_APPDIR                      = "XCurProcD";
 const FILE_BLOCKLIST                  = "blocklist.xml";
 
 const BRANCH_REGEXP                   = /^([^\.]+\.[0-9]+[a-z]*).*/gi;
@@ -1272,34 +1271,16 @@ var AddonManagerInternal = {
     uri = uri.replace(/%APP_VERSION%/g, aAppVersion ? aAppVersion :
                                                       Services.appinfo.version);
     uri = uri.replace(/%REQ_VERSION%/g, UPDATE_REQUEST_VERSION);
     uri = uri.replace(/%APP_OS%/g, Services.appinfo.OS);
     uri = uri.replace(/%APP_ABI%/g, xpcomABI);
     uri = uri.replace(/%APP_LOCALE%/g, getLocale());
     uri = uri.replace(/%CURRENT_APP_VERSION%/g, Services.appinfo.version);
 
-    // Replace custom parameters (names of custom parameters must have at
-    // least 3 characters to prevent lookups for something like %D0%C8)
-    var catMan = null;
-    uri = uri.replace(/%(\w{3,})%/g, function(aMatch, aParam) {
-      if (!catMan) {
-        catMan = Cc["@mozilla.org/categorymanager;1"].
-                 getService(Ci.nsICategoryManager);
-      }
-
-      try {
-        var contractID = catMan.getCategoryEntry(CATEGORY_UPDATE_PARAMS, aParam);
-        var paramHandler = Cc[contractID].getService(Ci.nsIPropertyBag2);
-        return paramHandler.getPropertyAsAString(aParam);
-      } catch (e) {
-        return aMatch;
-      }
-    });
-
     // escape() does not properly encode + symbols in any embedded FVF strings.
     return uri.replace(/\+/g, "%2B");
   },
 
   _updatePromptHandler(info) {
     let oldPerms = info.existingAddon.userPermissions;
     if (!oldPerms) {
       // Updating from a legacy add-on, just let it proceed

deleted file mode 100644
--- a/toolkit/mozapps/extensions/test/xpcshell/test_bug384052.js
+++ /dev/null
@@ -1,97 +0,0 @@
-const CLASS_ID = Components.ID("{12345678-1234-1234-1234-123456789abc}");
-const CONTRACT_ID = "@mozilla.org/test-parameter-source;1";
-
-var testserver = AddonTestUtils.createHttpServer({hosts: ["example.com"]});
-
-var gTestURL = "http://example.com/update.json?itemID=%ITEM_ID%&custom1=%CUSTOM1%&custom2=%CUSTOM2%";
-var gExpectedQuery = "itemID=test@mozilla.org&custom1=custom_parameter_1&custom2=custom_parameter_2";
-var gSeenExpectedURL = false;
-
-var gComponentRegistrar = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
-var gCategoryManager = Cc["@mozilla.org/categorymanager;1"].getService(Ci.nsICategoryManager);
-
-// Factory for our parameter handler
-var paramHandlerFactory = {
-  QueryInterface(iid) {
-    if (iid.equals(Ci.nsIFactory) || iid.equals(Ci.nsISupports))
-      return this;
-
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  },
-
-  createInstance(outer, iid) {
-    var bag = Cc["@mozilla.org/hash-property-bag;1"].
-              createInstance(Ci.nsIWritablePropertyBag);
-    bag.setProperty("CUSTOM1", "custom_parameter_1");
-    bag.setProperty("CUSTOM2", "custom_parameter_2");
-    return bag.QueryInterface(iid);
-  }
-};
-
-function initTest() {
-  do_test_pending();
-  // Setup extension manager
-  createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "1.9");
-
-  // Configure the HTTP server.
-  testserver.registerPathHandler("/update.json", function(aRequest, aResponse) {
-    gSeenExpectedURL = aRequest.queryString == gExpectedQuery;
-    aResponse.setStatusLine(null, 404, "Not Found");
-  });
-
-  // Register our parameter handlers
-  gComponentRegistrar.registerFactory(CLASS_ID, "Test component", CONTRACT_ID, paramHandlerFactory);
-  gCategoryManager.addCategoryEntry("extension-update-params", "CUSTOM1", CONTRACT_ID, false, false);
-  gCategoryManager.addCategoryEntry("extension-update-params", "CUSTOM2", CONTRACT_ID, false, false);
-
-  // Install a test extension into the profile
-  let dir = gProfD.clone();
-  dir.append("extensions");
-  writeInstallRDFForExtension({
-    id: "test@mozilla.org",
-    version: "1.0",
-    name: "Test extension",
-    bootstrap: true,
-    updateURL: gTestURL,
-    targetApplications: [{
-      id: "xpcshell@tests.mozilla.org",
-      minVersion: "1",
-      maxVersion: "1"
-    }],
-  }, dir);
-
-  startupManager();
-}
-
-function shutdownTest() {
-  shutdownManager();
-
-  gComponentRegistrar.unregisterFactory(CLASS_ID, paramHandlerFactory);
-  gCategoryManager.deleteCategoryEntry("extension-update-params", "CUSTOM1", false);
-  gCategoryManager.deleteCategoryEntry("extension-update-params", "CUSTOM2", false);
-
-  do_test_finished();
-}
-
-function run_test() {
-  initTest();
-
-  AddonManager.getAddonByID("test@mozilla.org", function(item) {
-    // Initiate update
-    item.findUpdates({
-      onCompatibilityUpdateAvailable(addon) {
-        do_throw("Should not have seen a compatibility update");
-      },
-
-      onUpdateAvailable(addon, install) {
-        do_throw("Should not have seen an available update");
-      },
-
-      onUpdateFinished(addon, error) {
-        Assert.equal(error, AddonManager.UPDATE_STATUS_DOWNLOAD_ERROR);
-        Assert.ok(gSeenExpectedURL);
-        executeSoon(shutdownTest);
-      }
-    }, AddonManager.UPDATE_WHEN_USER_REQUESTED);
-  });
-}

--- a/toolkit/mozapps/extensions/test/xpcshell/xpcshell.ini
+++ b/toolkit/mozapps/extensions/test/xpcshell/xpcshell.ini
@@ -38,19 +38,16 @@ tags = blocklist
 requesttimeoutfactor = 2
 tags = blocklist
 [test_bootstrap.js]
 skip-if = true # Bug 1358846 Bug 1365021 Bug 676992
 [test_bootstrap_const.js]
 [test_bootstrap_globals.js]
 [test_bug1180901_2.js]
 skip-if = os != "win"
-[test_bug384052.js]
-# Bug 676992: test consistently hangs on Android
-skip-if = os == "android"
 [test_bug393285.js]
 # Bug 676992: test consistently hangs on Android
 skip-if = os == "android"
 tags = blocklist
 [test_bug397778.js]
 # Bug 676992: test consistently hangs on Android
 skip-if = os == "android"
 [test_bug406118.js]