diff --git a/dom/ipc/ContentChild.cpp b/dom/ipc/ContentChild.cpp
index 128b4532464..50caa03c4e4 100644
--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -192,6 +192,7 @@
 #include "mozilla/widget/PuppetBidiKeyboard.h"
 #include "mozilla/RemoteSpellCheckEngineChild.h"
 #include "GMPServiceChild.h"
+#include "gfxPlatform.h"
 
 using namespace mozilla;
 using namespace mozilla::docshell;
@@ -2905,6 +2906,15 @@ ContentChild::RecvEndDragSession(const bool& aDoneDrag,
   return true;
 }
 
+bool
+ContentChild::RecvTestGraphicsDeviceReset(const uint32_t& aResetReason)
+{
+#if defined(XP_WIN)
+  gfxPlatform::GetPlatform()->TestDeviceReset(DeviceResetReason(aResetReason));
+#endif
+  return true;
+}
+
 } // namespace dom
 } // namespace mozilla
 
diff --git a/dom/ipc/ContentChild.h b/dom/ipc/ContentChild.h
index 806d12fb694..94963c61fdc 100644
--- a/dom/ipc/ContentChild.h
+++ b/dom/ipc/ContentChild.h
@@ -469,6 +469,8 @@ public:
 
     virtual bool RecvGamepadUpdate(const GamepadChangeEvent& aGamepadEvent) override;
 
+    virtual bool RecvTestGraphicsDeviceReset(const uint32_t& aResetReason) override;
+
 private:
     virtual void ActorDestroy(ActorDestroyReason why) override;
 
diff --git a/dom/ipc/PContent.ipdl b/dom/ipc/PContent.ipdl
index d7b596b7225..ee2f39cf810 100644
--- a/dom/ipc/PContent.ipdl
+++ b/dom/ipc/PContent.ipdl
@@ -650,6 +650,12 @@ child:
      * Send gamepad status update to child.
      */
     GamepadUpdate(GamepadChangeEvent aGamepadEvent);
+
+    /**
+     * Tell the child that for testing purposes, a graphics device reset has
+     * occurred.
+     */
+    async TestGraphicsDeviceReset(uint32_t aReason);
 parent:
     /**
      * Tell the content process some attributes of itself.  This is
diff --git a/gfx/thebes/gfxPlatform.h b/gfx/thebes/gfxPlatform.h
index 23a57cebdd8..1fd51509ffc 100644
--- a/gfx/thebes/gfxPlatform.h
+++ b/gfx/thebes/gfxPlatform.h
@@ -642,6 +642,10 @@ public:
       return mCompositorBackend;
     }
 
+    // Trigger a test-driven graphics device reset.
+    virtual void TestDeviceReset(DeviceResetReason aReason)
+    {}
+
 protected:
     gfxPlatform();
     virtual ~gfxPlatform();
diff --git a/gfx/thebes/gfxPrefs.h b/gfx/thebes/gfxPrefs.h
index bc97d6de2b4..d326ca3966b 100644
--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -242,6 +242,7 @@ private:
   // Note that        "gfx.logging.level" is defined in Logging.h
   DECL_GFX_PREF(Once, "gfx.logging.crash.length",              GfxLoggingCrashLength, uint32_t, 6);
   DECL_GFX_PREF(Live, "gfx.perf-warnings.enabled",             PerfWarnings, bool, false);
+  DECL_GFX_PREF(Live, "gfx.testing.device-reset",              DeviceResetForTesting, int32_t, 0);
   DECL_GFX_PREF(Once, "gfx.touch.resample",                    TouchResampling, bool, false);
 
   // These times should be in milliseconds
diff --git a/gfx/thebes/gfxWindowsPlatform.cpp b/gfx/thebes/gfxWindowsPlatform.cpp
index 79c5fcb34b5..14803f9ae65 100755
--- a/gfx/thebes/gfxWindowsPlatform.cpp
+++ b/gfx/thebes/gfxWindowsPlatform.cpp
@@ -74,6 +74,7 @@
 
 #include "VsyncSource.h"
 #include "DriverInitCrashDetection.h"
+#include "mozilla/dom/ContentParent.h"
 
 using namespace mozilla;
 using namespace mozilla::gfx;
@@ -376,6 +377,7 @@ gfxWindowsPlatform::gfxWindowsPlatform()
   : mRenderMode(RENDER_GDI)
   , mIsWARP(false)
   , mHasDeviceReset(false)
+  , mHasFakeDeviceReset(false)
   , mDoesD3D11TextureSharingWork(false)
   , mAcceleration(FeatureStatus::Unused)
   , mD3D11Status(FeatureStatus::Unused)
@@ -482,7 +484,19 @@ gfxWindowsPlatform::HandleDeviceReset()
     return false;
   }
 
-  Telemetry::Accumulate(Telemetry::DEVICE_RESET_REASON, uint32_t(resetReason));
+  if (mHasFakeDeviceReset) {
+    if (XRE_IsParentProcess()) {
+      // Notify child processes that we got a device reset.
+      nsTArray<dom::ContentParent*> processes;
+      dom::ContentParent::GetAll(processes);
+
+      for (size_t i = 0; i < processes.Length(); i++) {
+        processes[i]->SendTestGraphicsDeviceReset(uint32_t(resetReason));
+      }
+    }
+  } else {
+    Telemetry::Accumulate(Telemetry::DEVICE_RESET_REASON, uint32_t(resetReason));
+  }
 
   // Remove devices and adapters.
   mD3D10Device = nullptr;
@@ -497,6 +511,7 @@ gfxWindowsPlatform::HandleDeviceReset()
   // will be recomputed by InitializeDevices().
   mIsWARP = false;
   mHasDeviceReset = false;
+  mHasFakeDeviceReset = false;
   mDoesD3D11TextureSharingWork = false;
   mDeviceResetReason = DeviceResetReason::OK;
 
@@ -1109,6 +1124,17 @@ gfxWindowsPlatform::IsDeviceReset(HRESULT hr, DeviceResetReason* aResetReason)
   return false;
 }
 
+void
+gfxWindowsPlatform::TestDeviceReset(DeviceResetReason aReason)
+{
+  if (mHasDeviceReset) {
+    return;
+  }
+  mHasDeviceReset = true;
+  mHasFakeDeviceReset = true;
+  mDeviceResetReason = aReason;
+}
+
 bool
 gfxWindowsPlatform::DidRenderingDeviceReset(DeviceResetReason* aResetReason)
 {
@@ -1140,6 +1166,14 @@ gfxWindowsPlatform::DidRenderingDeviceReset(DeviceResetReason* aResetReason)
       return true;
     }
   }
+  if (XRE_IsParentProcess() && gfxPrefs::DeviceResetForTesting()) {
+    TestDeviceReset((DeviceResetReason)gfxPrefs::DeviceResetForTesting());
+    if (aResetReason) {
+      *aResetReason = mDeviceResetReason;
+    }
+    gfxPrefs::SetDeviceResetForTesting(0);
+    return true;
+  }
   return false;
 }
 
diff --git a/gfx/thebes/gfxWindowsPlatform.h b/gfx/thebes/gfxWindowsPlatform.h
index 127e7189f39..388bed8aac8 100644
--- a/gfx/thebes/gfxWindowsPlatform.h
+++ b/gfx/thebes/gfxWindowsPlatform.h
@@ -275,6 +275,8 @@ public:
     mozilla::gfx::FeatureStatus GetD2D1Status() const;
     unsigned GetD3D11Version();
 
+    void TestDeviceReset(DeviceResetReason aReason) override;
+
     virtual already_AddRefed<mozilla::gfx::VsyncSource> CreateHardwareVsyncSource() override;
     static mozilla::Atomic<size_t> sD3D11MemoryUsed;
     static mozilla::Atomic<size_t> sD3D9MemoryUsed;
@@ -334,6 +336,7 @@ private:
     mozilla::RefPtr<mozilla::layers::ReadbackManagerD3D11> mD3D11ReadbackManager;
     bool mIsWARP;
     bool mHasDeviceReset;
+    bool mHasFakeDeviceReset;
     bool mDoesD3D11TextureSharingWork;
     DeviceResetReason mDeviceResetReason;