--- a/toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js
+++ b/toolkit/components/url-classifier/nsUrlClassifierHashCompleter.js
@@ -221,19 +221,21 @@ HashCompleter.prototype = {
 
     if (!this._backoffs[aGethashUrl]) {
       // Initialize request backoffs separately, since requests are deleted
       // after they are dispatched.
       var jslib = Cc["@mozilla.org/url-classifier/jslib;1"]
                   .getService().wrappedJSObject;
 
       // Using the V4 backoff algorithm for both V2 and V4. See bug 1273398.
-      this._backoffs[aGethashUrl] = new jslib.RequestBackoffV4(
-        10 /* keep track of max requests */,
-        0 /* don't throttle on successful requests per time period */);
+      this._backoffs[aGethashUrl] = provider === "test" ?
+        new jslib.RequestBackoffTest() :
+        new jslib.RequestBackoffV4(
+          10 /* keep track of max requests */,
+          0 /* don't throttle on successful requests per time period */);
     }
 
     if (!this._nextGethashTimeMs[aGethashUrl]) {
       this._nextGethashTimeMs[aGethashUrl] = 0;
     }
 
     // Start off this request. Without dispatching to a thread, every call to
     // complete makes an individual HTTP request.

--- a/toolkit/components/url-classifier/nsUrlClassifierLib.js
+++ b/toolkit/components/url-classifier/nsUrlClassifierLib.js
@@ -184,16 +184,24 @@ function RequestBackoffV4(maxRequests, r
                 retryInterval /* retry interval, 15~30 min */,
                   maxRequests /* num requests */,
                 requestPeriod /* request time, 60 min */,
               backoffInterval /* backoff interval, 60 min */,
           24 * 60 * 60 * 1000 /* max backoff, 24hr */,
                          1000 /* tolerance of 1 sec */);
 }
 
+function RequestBackoffTest() {
+  let obj = new RequestBackoffV4(0, 0);
+  obj.canMakeRequest = function () {
+    return true;
+  }
+  return obj;
+}
+
 // Expose this whole component.
 var lib = this;
 
 function UrlClassifierLib() {
   this.wrappedJSObject = lib;
 }
 UrlClassifierLib.prototype.classID = Components.ID("{26a4a019-2827-4a89-a85c-5931a678823a}");
 UrlClassifierLib.prototype.QueryInterface = XPCOMUtils.generateQI([]);

--- a/toolkit/components/url-classifier/nsUrlClassifierListManager.js
+++ b/toolkit/components/url-classifier/nsUrlClassifierListManager.js
@@ -94,19 +94,21 @@ PROT_ListManager.prototype.registerTable
   this.tablesData[tableName].gethashUrl = gethashUrl;
   this.tablesData[tableName].provider = providerName;
 
   // Keep track of all of our update URLs.
   if (!this.needsUpdate_[updateUrl]) {
     this.needsUpdate_[updateUrl] = {};
 
     // Using the V4 backoff algorithm for both V2 and V4. See bug 1273398.
-    this.requestBackoffs_[updateUrl] = new RequestBackoffV4(
-                                            4 /* num requests */,
-                               60 * 60 * 1000 /* request time, 60 min */);
+    this.requestBackoffs_[updateUrl] = providerName == "test" ?
+      new RequestBackoffTest() :
+      new RequestBackoffV4(
+        4 /* num requests */,
+        60 * 60 * 1000 /* request time, 60 min */);
   }
   this.needsUpdate_[updateUrl][tableName] = false;
 
   return true;
 };
 
 /**
  * Unregister a table table from list
@@ -690,16 +692,17 @@ PROT_ListManager.prototype.QueryInterfac
 var modScope = this;
 function Init() {
   // Pull the library in.
   var jslib = Cc["@mozilla.org/url-classifier/jslib;1"]
               .getService().wrappedJSObject;
   /* global BindToObject, RequestBackoffV4 */
   modScope.BindToObject = jslib.BindToObject;
   modScope.RequestBackoffV4 = jslib.RequestBackoffV4;
+  modScope.RequestBackoffTest = jslib.RequestBackoffTest;
 
   // We only need to call Init once.
   modScope.Init = function() {};
 }
 
 function RegistrationData() {
 }
 RegistrationData.prototype = {