--- a/mobile/android/components/SessionStore.js
+++ b/mobile/android/components/SessionStore.js
@@ -1227,16 +1227,17 @@ SessionStore.prototype = {
       }
 
       log("_writeFile() _write() returned, _pendingWrite = " + this._pendingWrite);
 
       // We don't use a stopwatch here since the calls are async and stopwatches can only manage
       // a single timer per histogram.
       Services.telemetry.getHistogramById("FX_SESSION_RESTORE_WRITE_FILE_MS").add(Math.round(stopWriteMs - startWriteMs));
       Services.obs.notifyObservers(null, "sessionstore-state-write-complete");
+      EventDispatcher.instance.sendRequest({type: "Session:DataWritten"});
       this._sessionDataIsGood = true;
     });
   },
 
   /**
    * Writes the session state to a disk file, using async or sync methods
    * @param aFile nsIFile used for saving the session
    * @param aFileTemp nsIFile used as a temporary file in writing the data

--- a/mobile/android/tests/browser/robocop/src/org/mozilla/gecko/tests/testSessionPrivateBrowsing.java
+++ b/mobile/android/tests/browser/robocop/src/org/mozilla/gecko/tests/testSessionPrivateBrowsing.java
@@ -1,27 +1,29 @@
 package org.mozilla.gecko.tests;
 
 import org.mozilla.gecko.Actions;
+import org.mozilla.gecko.EventDispatcher;
 import org.mozilla.gecko.GeckoApp;
 import org.mozilla.gecko.Tabs;
-import org.mozilla.gecko.tests.helpers.GeckoHelper;
 import org.mozilla.gecko.util.BundleEventListener;
 import org.mozilla.gecko.util.EventCallback;
 import org.mozilla.gecko.util.GeckoBundle;
 
 public class testSessionPrivateBrowsing extends UITest implements BundleEventListener {
     private static final String PRIVATE_TABS_EVENT = "PrivateBrowsing:Data";
     private static final String FLUSH_TABS_EVENT = "Session:FlushTabs";
+    private static final String DATA_WRITTEN_EVENT = "Session:DataWritten";
 
     private volatile TestStage mTestStage;
     private boolean mWait = true;
 
     public void testSessionPrivateBrowsing() {
-        GeckoHelper.blockForDelayedStartup();
+        // Wait until the initial session store activity caused by startup has quietened down.
+        runTestCycle(TestStage.WAIT_FOR_READY);
 
         // Attempt to get the session store into a known idle state by flushing any possibly
         // still pending writes.
         runTestCycle(TestStage.SETUP);
 
         // Flushing with no pending writes should yield a "no change" message.
         runTestCycle(TestStage.NO_CHANGE);
 
@@ -52,33 +54,35 @@ public class testSessionPrivateBrowsing 
             Tabs.getInstance().addTab();
         }
         pageLoad.blockForEvent();
         pageLoad.unregisterListener();
     }
 
     private void runTestCycle(final TestStage testStage) {
         mTestStage = testStage;
-        ((GeckoApp) getActivity()).getAppEventDispatcher()
-                .registerGeckoThreadListener(this, PRIVATE_TABS_EVENT);
-        getActions().sendGlobalEvent(FLUSH_TABS_EVENT, null);
+        getEventDispatcher().registerGeckoThreadListener(this, getExpectedEvent());
+        if (testStage != TestStage.WAIT_FOR_READY) {
+            getActions().sendGlobalEvent(FLUSH_TABS_EVENT, null);
+        }
         synchronized (this) {
             while (mWait) {
                 try {
                     wait();
                 } catch (InterruptedException e) { }
             }
             mWait = true;
         }
     }
 
 
     @Override
     public void handleMessage(String event, GeckoBundle message, EventCallback callback) {
-        mAsserter.is(event, PRIVATE_TABS_EVENT, "received " + PRIVATE_TABS_EVENT + " event");
+        final String expectedEvent = getExpectedEvent();
+        mAsserter.is(event, expectedEvent, "received " + expectedEvent + " event");
 
         switch (mTestStage) {
             case NO_CHANGE:
                 getAsserter().ok(message.getBoolean("noChange"),
                         "got expected no change event", null);
                 break;
 
             case NO_PRIVATE_TABS:
@@ -89,23 +93,32 @@ public class testSessionPrivateBrowsing 
                 break;
 
             case SOME_PRIVATE_TABS:
                 getAsserter().ok(message.getString("session") != null,
                         "got some private tabs data",null);
                 break;
         }
 
-        ((GeckoApp) getActivity()).getAppEventDispatcher()
-                .unregisterGeckoThreadListener(this, PRIVATE_TABS_EVENT);
+        getEventDispatcher().unregisterGeckoThreadListener(this, expectedEvent);
         synchronized (this) {
             mWait = false;
             notifyAll();
         }
     }
 
+    private String getExpectedEvent() {
+        return (mTestStage == TestStage.WAIT_FOR_READY) ? DATA_WRITTEN_EVENT : PRIVATE_TABS_EVENT;
+    }
+
+    private EventDispatcher getEventDispatcher() {
+        return (mTestStage == TestStage.WAIT_FOR_READY) ? EventDispatcher.getInstance()
+                : ((GeckoApp) getActivity()).getAppEventDispatcher();
+    }
+
     private enum TestStage {
+        WAIT_FOR_READY,
         SETUP,
         NO_CHANGE,
         NO_PRIVATE_TABS,
         SOME_PRIVATE_TABS,
     }
 }