diff --git a/docshell/base/nsDocShell.cpp b/docshell/base/nsDocShell.cpp
index b9d4be58b..caef26fa2 100644
--- a/docshell/base/nsDocShell.cpp
+++ b/docshell/base/nsDocShell.cpp
@@ -6024,11 +6024,6 @@ nsDocShell::SetIsActive(bool aIsActive)
 nsresult
 nsDocShell::SetIsActiveInternal(bool aIsActive, bool aIsHidden)
 {
-  // We disallow setting active on chrome docshells.
-  if (mItemType == nsIDocShellTreeItem::typeChrome) {
-    return NS_ERROR_INVALID_ARG;
-  }
-
   // Keep track ourselves.
   mIsActive = aIsActive;
 
diff --git a/layout/base/nsRefreshDriver.cpp b/layout/base/nsRefreshDriver.cpp
index 78520753b..befadc81e 100644
--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -426,9 +426,11 @@ private:
 
     void OnTimerStart()
     {
+#if(0)
       if (!XRE_IsParentProcess()) {
         mLastChildTick = TimeStamp::Now();
       }
+#endif
     }
 
   private:
@@ -436,6 +438,7 @@ private:
 
     void RecordTelemetryProbes(TimeStamp aVsyncTimestamp)
     {
+#if(0)
       MOZ_ASSERT(NS_IsMainThread());
     #ifndef ANDROID  /* bug 1142079 */
       if (XRE_IsParentProcess()) {
@@ -463,20 +466,21 @@ private:
         mVsyncRate = mVsyncRefreshDriverTimer->mVsyncChild->GetVsyncRate();
       }
     #endif
+#endif
     }
 
     void TickRefreshDriver(TimeStamp aVsyncTimestamp)
     {
       MOZ_ASSERT(NS_IsMainThread());
 
-      RecordTelemetryProbes(aVsyncTimestamp);
-      if (XRE_IsParentProcess()) {
+      //RecordTelemetryProbes(aVsyncTimestamp);
+      //if (XRE_IsParentProcess()) {
         MonitorAutoLock lock(mRefreshTickLock);
         aVsyncTimestamp = mRecentVsync;
         mProcessedVsync = true;
-      } else {
-        mLastChildTick = TimeStamp::Now();
-      }
+      //} else {
+      //  mLastChildTick = TimeStamp::Now();
+      //}
       MOZ_ASSERT(aVsyncTimestamp <= TimeStamp::Now());
 
       // We might have a problem that we call ~VsyncRefreshDriverTimer() before
@@ -500,9 +504,10 @@ private:
 
   virtual ~VsyncRefreshDriverTimer()
   {
-    if (XRE_IsParentProcess()) {
+    //if (XRE_IsParentProcess()) {
       mVsyncDispatcher->SetParentRefreshTimer(nullptr);
       mVsyncDispatcher = nullptr;
+#if(0)
     } else {
       // Since the PVsyncChild actors live through the life of the process, just
       // send the unobserveVsync message to disable vsync event. We don't need
@@ -512,6 +517,7 @@ private:
       mVsyncChild->SetVsyncObserver(nullptr);
       mVsyncChild = nullptr;
     }
+#endif
 
     // Detach current vsync timer from this VsyncObserver. The observer will no
     // longer tick this timer.
@@ -542,11 +548,11 @@ private:
     // Protect updates to `sActiveVsyncTimers`.
     MOZ_ASSERT(NS_IsMainThread());
 
-    if (XRE_IsParentProcess()) {
+    //if (XRE_IsParentProcess()) {
       mVsyncDispatcher->SetParentRefreshTimer(nullptr);
-    } else {
-      Unused << mVsyncChild->SendUnobserve();
-    }
+    //} else {
+    //  Unused << mVsyncChild->SendUnobserve();
+    //}
 
     MOZ_ASSERT(sActiveVsyncTimers > 0);
     --sActiveVsyncTimers;
@@ -679,6 +685,8 @@ protected:
 
   virtual void ScheduleNextTick(TimeStamp aNowTime)
   {
+    return; // speculative from bug 1352205 and TenFourFox issue 446
+
     if (mDisableAfterMilliseconds > 0.0 &&
         mNextTickDuration > mDisableAfterMilliseconds)
     {
@@ -828,14 +836,14 @@ CreateVsyncRefreshTimer()
     return;
   }
 
-  if (XRE_IsParentProcess()) {
+  //if (XRE_IsParentProcess()) {
     // Make sure all vsync systems are ready.
     gfxPlatform::GetPlatform();
     // In parent process, we don't need to use ipc. We can create the
     // VsyncRefreshDriverTimer directly.
     sRegularRateTimer = new VsyncRefreshDriverTimer();
     return;
-  }
+  //}
 
 #ifdef MOZ_NUWA_PROCESS
   // NUWA process will just use software timer. Use NuwaAddFinalConstructor()
@@ -935,7 +943,7 @@ nsRefreshDriver::GetThrottledTimerInterval()
   if (rate <= 0) {
     rate = DEFAULT_THROTTLED_FRAME_RATE;
   }
-  return 1000.0 / rate;
+  return 3000.0 / rate;
 }
 
 /* static */ mozilla::TimeDuration
@@ -1874,7 +1882,7 @@ nsRefreshDriver::Tick(int64_t aNowEpoch, TimeStamp aNowTime)
     }
   }
 
-#ifndef ANDROID  /* bug 1142079 */
+#if(0)
   mozilla::Telemetry::AccumulateTimeDelta(mozilla::Telemetry::REFRESH_DRIVER_TICK, mTickStart);
 #endif
 
diff --git a/toolkit/xre/nsEmbedFunctions.cpp b/toolkit/xre/nsEmbedFunctions.cpp
index e735bf626..2c1433919 100644
--- a/toolkit/xre/nsEmbedFunctions.cpp
+++ b/toolkit/xre/nsEmbedFunctions.cpp
@@ -237,6 +237,12 @@ XRE_SetProcessType(const char* aProcessTypeString)
        i < (int) ArrayLength(kGeckoProcessTypeString);
        ++i) {
     if (!strcmp(kGeckoProcessTypeString[i], aProcessTypeString)) {
+      // For purposes of TenFourFox issue 441, assert that we never, ever
+      // launch a child process (it would immediately crash anyway due to
+      // defective IPC, but let's be paranoid and make it crash predictably).
+      if (MOZ_UNLIKELY(static_cast<GeckoProcessType>(i) != GeckoProcessType_Default))
+        MOZ_CRASH("TenFourFox does not support E10S child processes.");
+
       sChildProcessType = static_cast<GeckoProcessType>(i);
       return;
     }
diff --git a/xpfe/appshell/nsAppShellService.cpp b/xpfe/appshell/nsAppShellService.cpp
index 5632ae8b2..7e5d81753 100644
--- a/xpfe/appshell/nsAppShellService.cpp
+++ b/xpfe/appshell/nsAppShellService.cpp
@@ -132,33 +132,30 @@ nsAppShellService::CreateHiddenWindowHelper(bool aIsPrivate)
   rv = NS_NewURI(getter_AddRefs(url), hiddenWindowURL);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  RefPtr<nsWebShellWindow> newWindow;
-  if (!aIsPrivate) {
-    rv = JustCreateTopWindow(nullptr, url,
-                             chromeMask, initialWidth, initialHeight,
-                             true, nullptr, getter_AddRefs(newWindow));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    mHiddenWindow.swap(newWindow);
-  } else {
-    // Create the hidden private window
+  if (aIsPrivate) {
     chromeMask |= nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW;
-
-    rv = JustCreateTopWindow(nullptr, url,
-                             chromeMask, initialWidth, initialHeight,
-                             true, nullptr, getter_AddRefs(newWindow));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    nsCOMPtr<nsIDocShell> docShell;
-    newWindow->GetDocShell(getter_AddRefs(docShell));
-    if (docShell) {
-      docShell->SetAffectPrivateSessionLifetime(false);
-    }
-
-    mHiddenPrivateWindow.swap(newWindow);
   }
 
-  // RegisterTopLevelWindow(newWindow); -- Mac only
+  RefPtr<nsWebShellWindow> newWindow;
+  rv = JustCreateTopWindow(nullptr, url,
+                           chromeMask, initialWidth, initialHeight,
+                           true, nullptr, getter_AddRefs(newWindow));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIDocShell> docShell;
+  newWindow->GetDocShell(getter_AddRefs(docShell));
+  if (docShell) {
+    docShell->SetIsActive(false);
+    if (aIsPrivate) {
+      docShell->SetAffectPrivateSessionLifetime(false);
+    }
+  }
+
+  if (aIsPrivate) {
+    mHiddenPrivateWindow.swap(newWindow);
+  } else {
+    mHiddenWindow.swap(newWindow);
+  }
 
   return NS_OK;
 }