diff --git a/toolkit/components/passwordmgr/LoginManagerContent.jsm b/toolkit/components/passwordmgr/LoginManagerContent.jsm
index c63c240a8ac..9a692f7e0c6 100644
--- a/toolkit/components/passwordmgr/LoginManagerContent.jsm
+++ b/toolkit/components/passwordmgr/LoginManagerContent.jsm
@@ -573,15 +573,15 @@ var LoginManagerContent = {
   /*
    * _fillform
    *
-   * Fill the form with the provided login information.
-   * The logins are returned so they can be reused for
-   * optimization. Success of action is also returned in format
-   * [success, foundLogins].
+   * Attempt to find the username and password fields in a form, and fill them
+   * in using the provided logins.
    *
    * - autofillForm denotes if we should fill the form in automatically
+   * - clobberPassword controls if an existing password value can be
+   *     overwritten
    * - userTriggered is an indication of whether this filling was triggered by
    *     the user
-   * - foundLogins is an array of nsILoginInfo
+   * - foundLogins is an array of nsILoginInfo that could be used for the form
    */
   _fillForm : function (form, autofillForm, clobberPassword,
                         userTriggered, foundLogins) {
@@ -613,7 +613,7 @@ var LoginManagerContent = {
     if (foundLogins.length == 0) {
       // We don't log() here since this is a very common case.
       recordAutofillResult(AUTOFILL_RESULT.NO_SAVED_LOGINS);
-      return [false, foundLogins];
+      return;
     }
 
     // Heuristically determine what the user/pass fields are
@@ -627,14 +627,14 @@ var LoginManagerContent = {
     if (passwordField == null) {
       log("not filling form, no password field found");
       recordAutofillResult(AUTOFILL_RESULT.NO_PASSWORD_FIELD);
-      return [false, foundLogins];
+      return;
     }
 
     // If the password field is disabled or read-only, there's nothing to do.
     if (passwordField.disabled || passwordField.readOnly) {
       log("not filling form, password field disabled or read-only");
       recordAutofillResult(AUTOFILL_RESULT.PASSWORD_DISABLED_READONLY);
-      return [false, foundLogins];
+      return;
     }
 
     // Discard logins which have username/password values that don't
@@ -662,7 +662,7 @@ var LoginManagerContent = {
     if (logins.length == 0) {
       log("form not filled, none of the logins fit in the field");
       recordAutofillResult(AUTOFILL_RESULT.NO_LOGINS_FIT);
-      return [false, foundLogins];
+      return;
     }
 
     // The reason we didn't end up filling the form, if any.  We include
@@ -683,7 +683,7 @@ var LoginManagerContent = {
                               passwordField, foundLogins, null);
       log("form not filled, the password field was already filled");
       recordAutofillResult(AUTOFILL_RESULT.EXISTING_PASSWORD);
-      return [false, foundLogins];
+      return;
     }
 
     // If the form has an autocomplete=off attribute in play, don't
@@ -770,16 +770,10 @@ var LoginManagerContent = {
       }
       didFillForm = true;
     } else if (selectedLogin && !autofillForm) {
-      // For when autofillForm is false, but we still have the information
-      // to fill a form, we notify observers.
       didntFillReason = "noAutofillForms";
-      Services.obs.notifyObservers(form, "passwordmgr-found-form", didntFillReason);
       log("autofillForms=false but form can be filled; notified observers");
     } else if (selectedLogin && isFormDisabled) {
-      // For when autocomplete is off, but we still have the information
-      // to fill a form, we notify observers.
       didntFillReason = "autocompleteOff";
-      Services.obs.notifyObservers(form, "passwordmgr-found-form", didntFillReason);
       log("autocomplete=off but form can be filled; notified observers");
     }
 
@@ -807,8 +801,6 @@ var LoginManagerContent = {
       }
       recordAutofillResult(autofillResult);
     }
-
-    return [didFillForm, foundLogins];
   },
 
 
diff --git a/toolkit/components/passwordmgr/nsILoginManager.idl b/toolkit/components/passwordmgr/nsILoginManager.idl
index 77c5dbbbc9c..2df13cf0361 100644
--- a/toolkit/components/passwordmgr/nsILoginManager.idl
+++ b/toolkit/components/passwordmgr/nsILoginManager.idl
@@ -13,7 +13,7 @@ interface nsIDOMHTMLInputElement;
 interface nsIDOMHTMLFormElement;
 interface nsIPropertyBag;
 
-[scriptable, uuid(f0c5ca21-db71-4b32-993e-ab63054cc6f5)]
+[scriptable, uuid(38c7f6af-7df9-49c7-b558-2776b24e6cc1)]
 interface nsILoginManager : nsISupports {
   /**
    * This promise is resolved when initialization is complete, and is rejected
@@ -215,16 +215,6 @@ interface nsILoginManager : nsISupports {
                                in nsIDOMHTMLInputElement aElement,
                                in nsIFormAutoCompleteObserver aListener);
 
-  /**
-   * Fill a form with login information if we have it. This method will fill
-   * aForm regardless of the signon.autofillForms preference.
-   *
-   * @param aForm
-   *        The form to fill
-   * @return Promise that is resolved with whether or not the form was filled.
-   */
-  jsval fillForm(in nsIDOMHTMLFormElement aForm);
-
   /**
    * Search for logins in the login manager. An array is always returned;
    * if there are no logins the array is empty.
diff --git a/toolkit/components/passwordmgr/test/mochitest.ini b/toolkit/components/passwordmgr/test/mochitest.ini
index 912ff386644..5a0475b3b51 100644
--- a/toolkit/components/passwordmgr/test/mochitest.ini
+++ b/toolkit/components/passwordmgr/test/mochitest.ini
@@ -31,7 +31,6 @@ support-files =
 [test_basic_form_0pw.html]
 [test_basic_form_1pw.html]
 [test_basic_form_1pw_2.html]
-[test_basic_form_2.html]
 [test_basic_form_2pw_1.html]
 [test_basic_form_2pw_2.html]
 [test_basic_form_3pw_1.html]
@@ -40,7 +39,6 @@ skip-if = toolkit == 'android'
 [test_case_differences.html]
 skip-if = toolkit == 'android'
 [test_basic_form_html5.html]
-[test_basic_form_observer_autofillForms.html]
 [test_basic_form_observer_foundLogins.html]
 [test_basic_form_pwevent.html]
 [test_basic_form_pwonly.html]
diff --git a/toolkit/components/passwordmgr/test/test_basic_form_2.html b/toolkit/components/passwordmgr/test/test_basic_form_2.html
deleted file mode 100644
index b8813fce341..00000000000
--- a/toolkit/components/passwordmgr/test/test_basic_form_2.html
+++ /dev/null
@@ -1,64 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for Login Manager</title>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>  
-  <script type="text/javascript" src="pwmgr_common.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-</head>
-<body>
-Login Manager test: simple form fill with autofillForms disabled
-<script>
-commonInit();
-SimpleTest.waitForExplicitFinish();
-
-var pwmgr = SpecialPowers.Cc["@mozilla.org/login-manager;1"]
-                         .getService(SpecialPowers.Ci.nsILoginManager);
-</script>
-
-<p id="display"></p>
-
-<div id="content" style="display: block">
-
-  <form id="form1" action="formtest.js">
-    <p>This is form 1.</p>
-    <input  type="text"       name="uname">
-    <input  type="password"   name="pword">
-
-    <button type="submit">Submit</button>
-    <button type="reset"> Reset </button>
-  </form>
-
-</div>
-
-<pre id="test">
-<script class="testbody" type="text/javascript">
-
-/** Test for Login Manager: simple form fill with autofillForms disabled **/
-
-function startTest(){
-  // Ensure the form is empty at start
-  is($_(1, "uname").value, "", "Checking for blank username");
-  is($_(1, "pword").value, "", "Checking for blank password");
-
-  // Call the public method, check return value
-  pwmgr.fillForm(document.getElementById("form1"))
-       .then(function(result) {
-         is(result, true, "Checking return value of fillForm");
-
-         // Check that the form was filled
-         is($_(1, "uname").value, "testuser", "Checking for filled username");
-         is($_(1, "pword").value, "testpass", "Checking for filled password");
-
-         SimpleTest.finish();
-       });
-}
-// Assume that the pref starts out true, so set to false
-SpecialPowers.pushPrefEnv({"set":[["signon.autofillForms", false]]}, setup);
-function setup() {
- window.addEventListener("runTests", startTest);
-}
-</script>
-</pre>
-</body>
-</html>
diff --git a/toolkit/components/passwordmgr/test/test_basic_form_observer_autofillForms.html b/toolkit/components/passwordmgr/test/test_basic_form_observer_autofillForms.html
deleted file mode 100644
index 75e13ef5061..00000000000
--- a/toolkit/components/passwordmgr/test/test_basic_form_observer_autofillForms.html
+++ /dev/null
@@ -1,104 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for Login Manager</title>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>  
-  <script type="text/javascript" src="pwmgr_common.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
-</head>
-<body>
-Login Manager test: simple form with autofillForms disabled and notifying observers
-<script>
-commonInit(true);
-SimpleTest.waitForExplicitFinish();
-
-const Cc = SpecialPowers.Cc;
-const Ci = SpecialPowers.Ci;
-var TestObserver;
-// Assume that the pref starts out true, so set to false
-SpecialPowers.pushPrefEnv({"set":[["signon.autofillForms", false]]}, function() {
-  TestObserver = {
-  receivedNotificationFoundForm : false,
-  receivedNotificationFoundLogins : false,
-  dataFoundForm : "",
-  dataFoundLogins : null,
-  observe : function (subject, topic, data) {
-    var pwmgr = Cc["@mozilla.org/login-manager;1"].
-                getService(Ci.nsILoginManager);
-    if (topic == "passwordmgr-found-form") {
-      info("got passwordmgr-found-form");
-      this.receivedNotificationFoundForm = true;
-      this.dataFoundForm = data;
-      // Now fill the form
-      pwmgr.fillForm(subject)
-           .then(window.startTest)
-           .then(null, function(e) { alert(e); });
-    } else if (topic == "passwordmgr-found-logins") {
-      info("got passwordmgr-found-logins");
-
-      // We only care about the first notification (the second comes from our
-      // own call to pwmgr.fillForm.
-      if (this.receivedNotificationFoundLogins)
-        return;
-      this.receivedNotificationFoundLogins = true;
-      this.dataFoundLogins = subject.QueryInterface(Ci.nsIPropertyBag2);
-    }
-  }
-};
-
-// Add the observer
-SpecialPowers.addObserver(TestObserver, "passwordmgr-found-form", false);
-SpecialPowers.addObserver(TestObserver, "passwordmgr-found-logins", false);
-});
-</script>
-
-<p id="display"></p>
-
-<div id="content" style="display: block">
-
-  <form id="form1" action="formtest.js">
-    <p>This is form 1.</p>
-    <input  type="text"       name="uname">
-    <input  type="password"   name="pword">
-
-    <button type="submit">Submit</button>
-    <button type="reset"> Reset </button>
-  </form>
-
-</div>
-
-<pre id="test">
-<script class="testbody" type="text/javascript">
-
-/** Test for Login Manager: simple form with autofillForms disabled and notifying observers **/
-function startTest() {
-  // Test that found-form observer is notified & got correct data
-  is(TestObserver.receivedNotificationFoundForm, true, "Checking found-form observer was notified");
-  is(TestObserver.dataFoundForm, "noAutofillForms", "Checking found-form observer got correct data");
-
-  // Check that form1 was filled
-  is($_(1, "uname").value, "testuser", "Checking for filled username");
-  is($_(1, "pword").value, "testpass", "Checking for filled password");
-
-  // Test that found-logins observer is notified & got correct data
-  is(TestObserver.receivedNotificationFoundLogins, true, "Checking found-logins observer was notified");
-  is(TestObserver.dataFoundLogins.get("didntFillReason"), "noAutofillForms", "Checking didntFillReason is noAutofillForms");
-  is(SpecialPowers.unwrap(TestObserver.dataFoundLogins.get("usernameField")), $_(1, "uname"), "Checking username field is correct");
-  is(SpecialPowers.unwrap(TestObserver.dataFoundLogins.get("passwordField")), $_(1, "pword"), "Checking password field is correct");
-  is(TestObserver.dataFoundLogins.get("foundLogins").constructor.name, "Array", "Checking foundLogins is array");
-  is(TestObserver.dataFoundLogins.get("foundLogins").length, 1, "Checking foundLogins contains one login");
-  ok(TestObserver.dataFoundLogins.get("selectedLogin").QueryInterface(Ci.nsILoginInfo), "Checking selectedLogin is nsILoginInfo");
-  ok(TestObserver.dataFoundLogins.get("selectedLogin").equals(TestObserver.dataFoundLogins.get("foundLogins")[0]),
-     "Checking selectedLogin is found login");
-  // Remove the observer
-  SpecialPowers.removeObserver(TestObserver, "passwordmgr-found-form");
-  SpecialPowers.removeObserver(TestObserver, "passwordmgr-found-logins");
-
-  SimpleTest.finish();
-}
-
-
-</script>
-</pre>
-</body>
-</html>