diff --git a/dom/base/nsDOMWindowUtils.cpp b/dom/base/nsDOMWindowUtils.cpp
index ce8a5ad126a..2fb099538fa 100644
--- a/dom/base/nsDOMWindowUtils.cpp
+++ b/dom/base/nsDOMWindowUtils.cpp
@@ -3,13 +3,14 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "mozilla/layers/CompositorParent.h"
+#include "nsDOMWindowUtils.h"
+
+#include "mozilla/layers/CompositorChild.h"
 #include "mozilla/layers/LayerTransactionChild.h"
 #include "nsPresContext.h"
 #include "nsDOMClassInfoID.h"
 #include "nsError.h"
 #include "nsIDOMEvent.h"
-#include "nsDOMWindowUtils.h"
 #include "nsQueryContentEventResult.h"
 #include "CompositionStringSynthesizer.h"
 #include "nsGlobalWindow.h"
@@ -2548,7 +2549,14 @@ nsDOMWindowUtils::AdvanceTimeAndRefresh(int64_t aMilliseconds)
 
   nsRefreshDriver* driver = GetPresContext()->RefreshDriver();
   driver->AdvanceTimeAndRefresh(aMilliseconds);
-  CompositorParent::SetTimeAndSampleAnimations(driver->MostRecentRefresh(), true);
+
+  nsIWidget* widget = GetWidget();
+  if (widget) {
+    CompositorChild* compositor = widget->GetRemoteRenderer();
+    if (compositor) {
+      compositor->SendSetTestSampleTime(driver->MostRecentRefresh());
+    }
+  }
 
   return NS_OK;
 }
@@ -2560,9 +2568,19 @@ nsDOMWindowUtils::RestoreNormalRefresh()
     return NS_ERROR_DOM_SECURITY_ERR;
   }
 
+  // Kick the compositor out of test mode before the refresh driver, so that
+  // the refresh driver doesn't send an update that gets ignored by the
+  // compositor.
+  nsIWidget* widget = GetWidget();
+  if (widget) {
+    CompositorChild* compositor = widget->GetRemoteRenderer();
+    if (compositor) {
+      compositor->SendLeaveTestMode();
+    }
+  }
+
   nsRefreshDriver* driver = GetPresContext()->RefreshDriver();
   driver->RestoreNormalRefresh();
-  CompositorParent::SetTimeAndSampleAnimations(driver->MostRecentRefresh(), false);
 
   return NS_OK;
 }
diff --git a/dom/base/nsDOMWindowUtils.h b/dom/base/nsDOMWindowUtils.h
index 21ddf7ee300..a7c7b7da033 100644
--- a/dom/base/nsDOMWindowUtils.h
+++ b/dom/base/nsDOMWindowUtils.h
@@ -10,9 +10,13 @@
 
 #include "nsIDOMWindowUtils.h"
 #include "mozilla/Attributes.h"
+#include "mozilla/BasicEvents.h"
 
 class nsGlobalWindow;
 class nsIPresShell;
+class nsIWidget;
+class nsPresContext;
+class nsPoint;
 
 class nsDOMWindowUtils MOZ_FINAL : public nsIDOMWindowUtils,
                                    public nsSupportsWeakReference
diff --git a/gfx/layers/ipc/CompositorParent.cpp b/gfx/layers/ipc/CompositorParent.cpp
index cb8a6194b33..758c691fce1 100644
--- a/gfx/layers/ipc/CompositorParent.cpp
+++ b/gfx/layers/ipc/CompositorParent.cpp
@@ -373,6 +373,28 @@ CompositorParent::RecvStopFrameTimeRecording(const uint32_t& aStartIndex,
   return true;
 }
 
+bool
+CompositorParent::RecvSetTestSampleTime(const TimeStamp& aTime)
+{
+  if (aTime.IsNull()) {
+    return false;
+  }
+
+  mIsTesting = true;
+  mTestTime = aTime;
+  if (mCompositionManager) {
+    mCompositionManager->TransformShadowTree(aTime);
+  }
+  return true;
+}
+
+bool
+CompositorParent::RecvLeaveTestMode()
+{
+  mIsTesting = false;
+  return true;
+}
+
 void
 CompositorParent::ActorDestroy(ActorDestroyReason why)
 {
@@ -863,21 +885,6 @@ CompositorParent* CompositorParent::RemoveCompositor(uint64_t id)
   return retval;
 }
 
-/* static */ void
-CompositorParent::SetTimeAndSampleAnimations(TimeStamp aTime, bool aIsTesting)
-{
-  if (!sCompositorMap) {
-    return;
-  }
-  for (CompositorMap::iterator it = sCompositorMap->begin(); it != sCompositorMap->end(); ++it) {
-    it->second->mIsTesting = aIsTesting;
-    it->second->mTestTime = aTime;
-    if (it->second->mCompositionManager) {
-      it->second->mCompositionManager->TransformShadowTree(aTime);
-    }
-  }
-}
-
 bool
 CompositorParent::RecvNotifyChildCreated(const uint64_t& child)
 {
@@ -1013,6 +1020,8 @@ public:
   virtual bool RecvNotifyRegionInvalidated(const nsIntRegion& aRegion) { return true; }
   virtual bool RecvStartFrameTimeRecording(const int32_t& aBufferSize, uint32_t* aOutStartIndex) MOZ_OVERRIDE { return true; }
   virtual bool RecvStopFrameTimeRecording(const uint32_t& aStartIndex, InfallibleTArray<float>* intervals) MOZ_OVERRIDE  { return true; }
+  virtual bool RecvSetTestSampleTime(const TimeStamp& aTime) MOZ_OVERRIDE { return true; }
+  virtual bool RecvLeaveTestMode() MOZ_OVERRIDE { return true; }
 
   virtual PLayerTransactionParent*
     AllocPLayerTransactionParent(const nsTArray<LayersBackend>& aBackendHints,
diff --git a/gfx/layers/ipc/CompositorParent.h b/gfx/layers/ipc/CompositorParent.h
index 259f522ad62..3336ce6b121 100644
--- a/gfx/layers/ipc/CompositorParent.h
+++ b/gfx/layers/ipc/CompositorParent.h
@@ -93,6 +93,8 @@ public:
   virtual bool RecvNotifyRegionInvalidated(const nsIntRegion& aRegion) MOZ_OVERRIDE;
   virtual bool RecvStartFrameTimeRecording(const int32_t& aBufferSize, uint32_t* aOutStartIndex) MOZ_OVERRIDE;
   virtual bool RecvStopFrameTimeRecording(const uint32_t& aStartIndex, InfallibleTArray<float>* intervals) MOZ_OVERRIDE;
+  virtual bool RecvSetTestSampleTime(const TimeStamp& aTime) MOZ_OVERRIDE;
+  virtual bool RecvLeaveTestMode() MOZ_OVERRIDE;
 
   virtual void ActorDestroy(ActorDestroyReason why) MOZ_OVERRIDE;
 
@@ -222,19 +224,11 @@ public:
 
   float ComputeRenderIntegrity();
 
-  /**
-   * Tell all CompositorParents to update their last refresh to aTime and sample
-   * animations at this time stamp.  If aIsTesting is true, the
-   * CompositorParents will become "paused" and continue sampling animations at
-   * this time stamp until this function is called again with aIsTesting set to
-   * false.
-   */
-  static void SetTimeAndSampleAnimations(TimeStamp aTime, bool aIsTesting);
-
   /**
    * Returns true if the calling thread is the compositor thread.
    */
   static bool IsInCompositorThread();
+
 protected:
   virtual PLayerTransactionParent*
     AllocPLayerTransactionParent(const nsTArray<LayersBackend>& aBackendHints,
diff --git a/gfx/layers/ipc/PCompositor.ipdl b/gfx/layers/ipc/PCompositor.ipdl
index af2c3422b6e..5e0e20ea8ba 100644
--- a/gfx/layers/ipc/PCompositor.ipdl
+++ b/gfx/layers/ipc/PCompositor.ipdl
@@ -18,6 +18,7 @@ using mozilla::layers::FrameMetrics::ViewID from "FrameMetrics.h";
 using mozilla::layers::LayersBackend from "mozilla/layers/LayersTypes.h";
 using mozilla::CrossProcessMutexHandle from "mozilla/ipc/CrossProcessMutex.h";
 using mozilla::ipc::SharedMemoryBasic::Handle from "mozilla/ipc/SharedMemoryBasic.h";
+using class mozilla::TimeStamp from "mozilla/TimeStamp.h";
 
 namespace mozilla {
 namespace layers {
@@ -77,6 +78,12 @@ parent:
   sync StopFrameTimeRecording(uint32_t startIndex)
     returns (float[] intervals);
 
+  // Enter test mode, set the sample time to sampleTime, and resample animations.
+  // sampleTime must not be null.
+  sync SetTestSampleTime(TimeStamp sampleTime);
+  // Leave test mode and resume normal compositing
+  sync LeaveTestMode();
+
   // layersBackendHints is an ordered list of preffered backends where
   // layersBackendHints[0] is the best backend. If any hints are LayersBackend::LAYERS_NONE
   // that hint is ignored.