--- a/toolkit/components/search/nsSearchService.js
+++ b/toolkit/components/search/nsSearchService.js
@@ -315,30 +315,25 @@ function loadListener(aChannel, aEngine,
 }
 loadListener.prototype = {
   _callback: null,
   _channel: null,
   _countRead: 0,
   _engine: null,
   _stream: null,
 
-  QueryInterface: function SRCH_loadQI(aIID) {
-    if (aIID.equals(Ci.nsISupports)           ||
-        aIID.equals(Ci.nsIRequestObserver)    ||
-        aIID.equals(Ci.nsIStreamListener)     ||
-        aIID.equals(Ci.nsIChannelEventSink)   ||
-        aIID.equals(Ci.nsIInterfaceRequestor) ||
-        // See FIXME comment below
-        aIID.equals(Ci.nsIHttpEventSink)      ||
-        aIID.equals(Ci.nsIProgressEventSink)  ||
-        false)
-      return this;
-
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  },
+  QueryInterface: XPCOMUtils.generateQI([
+    Ci.nsIRequestObserver,
+    Ci.nsIStreamListener,
+    Ci.nsIChannelEventSink,
+    Ci.nsIInterfaceRequestor,
+    // See FIXME comment below.
+    Ci.nsIHttpEventSink,
+    Ci.nsIProgressEventSink
+  ]),
 
   // nsIRequestObserver
   onStartRequest: function SRCH_loadStartR(aRequest, aContext) {
     LOG("loadListener: Starting request: " + aRequest.name);
     this._stream = Cc["@mozilla.org/binaryinputstream;1"].
                    createInstance(Ci.nsIBinaryInputStream);
   },
 
@@ -2527,22 +2522,17 @@ Engine.prototype = {
     return {
       mainDomain: templateUrl.host,
       path: templateUrl.filePath.toLowerCase(),
       termsParameterName: termsParameterName,
     };
   },
 
   // nsISupports
-  QueryInterface: function SRCH_ENG_QI(aIID) {
-    if (aIID.equals(Ci.nsISearchEngine) ||
-        aIID.equals(Ci.nsISupports))
-      return this;
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  },
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISearchEngine]),
 
   get wrappedJSObject() {
     return this;
   },
 
   /**
    * Returns a string with the URL to an engine's icon matching both width and
    * height. Returns null if icon with specified dimensions is not found.
@@ -2634,22 +2624,17 @@ function Submission(aURI, aPostData = nu
 }
 Submission.prototype = {
   get uri() {
     return this._uri;
   },
   get postData() {
     return this._postData;
   },
-  QueryInterface: function SRCH_SUBM_QI(aIID) {
-    if (aIID.equals(Ci.nsISearchSubmission) ||
-        aIID.equals(Ci.nsISupports))
-      return this;
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  }
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISearchSubmission])
 }
 
 // nsISearchParseSubmissionResult
 function ParseSubmissionResult(aEngine, aTerms, aTermsOffset, aTermsLength) {
   this._engine = aEngine;
   this._terms = aTerms;
   this._termsOffset = aTermsOffset;
   this._termsLength = aTermsLength;
@@ -4748,24 +4733,21 @@ SearchService.prototype = {
     Services.obs.removeObserver(this, SEARCH_ENGINE_TOPIC);
     Services.obs.removeObserver(this, QUIT_APPLICATION_TOPIC);
 
 #ifdef MOZ_FENNEC
     Services.prefs.removeObserver(LOCALE_PREF, this);
 #endif
   },
 
-  QueryInterface: function SRCH_SVC_QI(aIID) {
-    if (aIID.equals(Ci.nsIBrowserSearchService) ||
-        aIID.equals(Ci.nsIObserver)             ||
-        aIID.equals(Ci.nsITimerCallback)        ||
-        aIID.equals(Ci.nsISupports))
-      return this;
-    throw Cr.NS_ERROR_NO_INTERFACE;
-  }
+  QueryInterface: XPCOMUtils.generateQI([
+    Ci.nsIBrowserSearchService,
+    Ci.nsIObserver,
+    Ci.nsITimerCallback
+  ])
 };
 
 
 const SEARCH_UPDATE_LOG_PREFIX = "*** Search update: ";
 
 /**
  * Outputs aText to the JavaScript console as well as to stdout, if the search
  * logging pref (browser.search.update.log) is set to true.