--- a/dom/media/webspeech/synth/ipc/PSpeechSynthesisRequest.ipdl
+++ b/dom/media/webspeech/synth/ipc/PSpeechSynthesisRequest.ipdl
@@ -10,29 +10,31 @@ namespace mozilla {
 namespace dom {
 
 async protocol PSpeechSynthesisRequest
 {
   manager PSpeechSynthesis;
 
  parent:
 
+  __delete__();
+
   Pause();
 
   Resume();
 
   Cancel();
 
   ForceEnd();
 
   SetAudioOutputVolume(float aVolume);
 
  child:
 
-  __delete__(bool aIsError, float aElapsedTime, uint32_t aCharIndex);
+  OnEnd(bool aIsError, float aElapsedTime, uint32_t aCharIndex);
 
   OnStart(nsString aUri);
 
   OnPause(float aElapsedTime, uint32_t aCharIndex);
 
   OnResume(float aElapsedTime, uint32_t aCharIndex);
 
   OnBoundary(nsString aName, float aElapsedTime, uint32_t aCharIndex);

--- a/dom/media/webspeech/synth/ipc/SpeechSynthesisChild.cpp
+++ b/dom/media/webspeech/synth/ipc/SpeechSynthesisChild.cpp
@@ -82,28 +82,31 @@ SpeechSynthesisRequestChild::~SpeechSynt
 bool
 SpeechSynthesisRequestChild::RecvOnStart(const nsString& aUri)
 {
   mTask->DispatchStartImpl(aUri);
   return true;
 }
 
 bool
-SpeechSynthesisRequestChild::Recv__delete__(const bool& aIsError,
-                                            const float& aElapsedTime,
-                                            const uint32_t& aCharIndex)
+SpeechSynthesisRequestChild::RecvOnEnd(const bool& aIsError,
+                                       const float& aElapsedTime,
+                                       const uint32_t& aCharIndex)
 {
+  SpeechSynthesisRequestChild* actor = mTask->mActor;
   mTask->mActor = nullptr;
 
   if (aIsError) {
     mTask->DispatchErrorImpl(aElapsedTime, aCharIndex);
   } else {
     mTask->DispatchEndImpl(aElapsedTime, aCharIndex);
   }
 
+  actor->Send__delete__(actor);
+
   return true;
 }
 
 bool
 SpeechSynthesisRequestChild::RecvOnPause(const float& aElapsedTime,
                                          const uint32_t& aCharIndex)
 {
   mTask->DispatchPauseImpl(aElapsedTime, aCharIndex);

--- a/dom/media/webspeech/synth/ipc/SpeechSynthesisChild.h
+++ b/dom/media/webspeech/synth/ipc/SpeechSynthesisChild.h
@@ -47,19 +47,19 @@ class SpeechSynthesisRequestChild : publ
 {
 public:
   explicit SpeechSynthesisRequestChild(SpeechTaskChild* aTask);
   virtual ~SpeechSynthesisRequestChild();
 
 protected:
   virtual bool RecvOnStart(const nsString& aUri) override;
 
-  virtual bool Recv__delete__(const bool& aIsError,
-                              const float& aElapsedTime,
-                              const uint32_t& aCharIndex) override;
+  virtual bool RecvOnEnd(const bool& aIsError,
+                         const float& aElapsedTime,
+                         const uint32_t& aCharIndex) override;
 
   virtual bool RecvOnPause(const float& aElapsedTime, const uint32_t& aCharIndex) override;
 
   virtual bool RecvOnResume(const float& aElapsedTime, const uint32_t& aCharIndex) override;
 
   virtual bool RecvOnBoundary(const nsString& aName, const float& aElapsedTime,
                               const uint32_t& aCharIndex) override;
 

--- a/dom/media/webspeech/synth/ipc/SpeechSynthesisParent.cpp
+++ b/dom/media/webspeech/synth/ipc/SpeechSynthesisParent.cpp
@@ -77,19 +77,16 @@ SpeechSynthesisRequestParent::SpeechSynt
   : mTask(aTask)
 {
   mTask->mActor = this;
   MOZ_COUNT_CTOR(SpeechSynthesisRequestParent);
 }
 
 SpeechSynthesisRequestParent::~SpeechSynthesisRequestParent()
 {
-  if (mTask && mTask->mActor) {
-    mTask->mActor = nullptr;
-  }
 
   MOZ_COUNT_DTOR(SpeechSynthesisRequestParent);
 }
 
 void
 SpeechSynthesisRequestParent::ActorDestroy(ActorDestroyReason aWhy)
 {
   // Implement me! Bug 1005141
@@ -99,16 +96,25 @@ bool
 SpeechSynthesisRequestParent::RecvPause()
 {
   MOZ_ASSERT(mTask);
   mTask->Pause();
   return true;
 }
 
 bool
+SpeechSynthesisRequestParent::Recv__delete__()
+{
+  MOZ_ASSERT(mTask);
+  mTask->mActor = nullptr;
+  mTask = nullptr;
+  return true;
+}
+
+bool
 SpeechSynthesisRequestParent::RecvResume()
 {
   MOZ_ASSERT(mTask);
   mTask->Resume();
   return true;
 }
 
 bool
@@ -147,19 +153,17 @@ SpeechTaskParent::DispatchStartImpl(cons
 
   return NS_OK;
 }
 
 nsresult
 SpeechTaskParent::DispatchEndImpl(float aElapsedTime, uint32_t aCharIndex)
 {
   MOZ_ASSERT(mActor);
-  SpeechSynthesisRequestParent* actor = mActor;
-  mActor = nullptr;
-  if(NS_WARN_IF(!(actor->Send__delete__(actor, false, aElapsedTime, aCharIndex)))) {
+  if(NS_WARN_IF(!(mActor->SendOnEnd(false, aElapsedTime, aCharIndex)))) {
     return NS_ERROR_FAILURE;
   }
 
   return NS_OK;
 }
 
 nsresult
 SpeechTaskParent::DispatchPauseImpl(float aElapsedTime, uint32_t aCharIndex)
@@ -182,19 +186,17 @@ SpeechTaskParent::DispatchResumeImpl(flo
 
   return NS_OK;
 }
 
 nsresult
 SpeechTaskParent::DispatchErrorImpl(float aElapsedTime, uint32_t aCharIndex)
 {
   MOZ_ASSERT(mActor);
-  SpeechSynthesisRequestParent* actor = mActor;
-  mActor = nullptr;
-  if(NS_WARN_IF(!(actor->Send__delete__(actor, true, aElapsedTime, aCharIndex)))) {
+  if(NS_WARN_IF(!(mActor->SendOnEnd(true, aElapsedTime, aCharIndex)))) {
     return NS_ERROR_FAILURE;
   }
 
   return NS_OK;
 }
 
 nsresult
 SpeechTaskParent::DispatchBoundaryImpl(const nsAString& aName,

--- a/dom/media/webspeech/synth/ipc/SpeechSynthesisParent.h
+++ b/dom/media/webspeech/synth/ipc/SpeechSynthesisParent.h
@@ -66,16 +66,18 @@ protected:
 
   virtual bool RecvResume() override;
 
   virtual bool RecvCancel() override;
 
   virtual bool RecvForceEnd() override;
 
   virtual bool RecvSetAudioOutputVolume(const float& aVolume) override;
+
+  virtual bool Recv__delete__() override;
 };
 
 class SpeechTaskParent : public nsSpeechTask
 {
   friend class SpeechSynthesisRequestParent;
 public:
   SpeechTaskParent(float aVolume, const nsAString& aUtterance)
     : nsSpeechTask(aVolume, aUtterance) {}

new file mode 100644
--- /dev/null
+++ b/dom/media/webspeech/synth/test/file_speech_error.html
@@ -0,0 +1,46 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1226015
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1226015</title>
+  <script type="application/javascript">
+    window.SimpleTest = parent.SimpleTest;
+    window.info = parent.info;
+    window.is = parent.is;
+    window.isnot = parent.isnot;
+    window.ok = parent.ok;
+  </script>
+  <script type="application/javascript" src="common.js"></script>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1226015">Mozilla Bug 1226015</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+<script type="application/javascript">
+
+/** Test for Bug 1226015 **/
+
+function testFunc(done_cb) {
+  var utterance = new SpeechSynthesisUtterance();
+  utterance.lang = 'it-IT-error';
+
+  speechSynthesis.speak(utterance);
+  speechSynthesis.cancel();
+
+  ok(true, "we didn't crash, that is good.")
+  SimpleTest.finish();
+}
+
+// Run test with no global queue, and then run it with a global queue.
+testFunc();
+
+</script>
+</pre>
+</body>
+</html>

--- a/dom/media/webspeech/synth/test/mochitest.ini
+++ b/dom/media/webspeech/synth/test/mochitest.ini
@@ -1,21 +1,23 @@
 [DEFAULT]
 tags=msg
 support-files =
   common.js
   file_setup.html
   file_speech_queue.html
   file_speech_simple.html
   file_speech_cancel.html
+  file_speech_error.html
   file_indirect_service_events.html
   file_global_queue.html
   file_global_queue_cancel.html
   file_global_queue_pause.html
 
 [test_setup.html]
 [test_speech_queue.html]
 [test_speech_simple.html]
 [test_speech_cancel.html]
+[test_speech_error.html]
 [test_indirect_service_events.html]
 [test_global_queue.html]
 [test_global_queue_cancel.html]
 [test_global_queue_pause.html]

--- a/dom/media/webspeech/synth/test/nsFakeSynthServices.cpp
+++ b/dom/media/webspeech/synth/test/nsFakeSynthServices.cpp
@@ -25,17 +25,18 @@
 namespace mozilla {
 namespace dom {
 
 StaticRefPtr<nsFakeSynthServices> nsFakeSynthServices::sSingleton;
 
 enum VoiceFlags
 {
   eSuppressEvents = 1,
-  eSuppressEnd = 2
+  eSuppressEnd = 2,
+  eFailAtStart = 4
 };
 
 struct VoiceDetails
 {
   const char* uri;
   const char* name;
   const char* lang;
   bool defaultVoice;
@@ -49,16 +50,17 @@ static const VoiceDetails sDirectVoices[
   {"urn:moz-tts:fake-direct:celine", "Celine Dion", "fr-CA", false, 0},
   {"urn:moz-tts:fake-direct:julie", "Julieta Venegas", "es-MX", false, },
 };
 
 static const VoiceDetails sIndirectVoices[] = {
   {"urn:moz-tts:fake-indirect:zanetta", "Zanetta Farussi", "it-IT", false, 0},
   {"urn:moz-tts:fake-indirect:margherita", "Margherita Durastanti", "it-IT-noevents-noend", false, eSuppressEvents | eSuppressEnd},
   {"urn:moz-tts:fake-indirect:teresa", "Teresa Cornelys", "it-IT-noend", false, eSuppressEnd},
+  {"urn:moz-tts:fake-indirect:cecilia", "Cecilia Bartoli", "it-IT-error", false, eFailAtStart},
 };
 
 // FakeSynthCallback
 class FakeSynthCallback : public nsISpeechTaskCallback
 {
 public:
   explicit FakeSynthCallback(nsISpeechTask* aTask) : mTask(aTask) { }
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
@@ -238,16 +240,21 @@ FakeIndirectAudioSynth::Speak(const nsAS
 
   uint32_t flags = 0;
   for (uint32_t i = 0; i < ArrayLength(sIndirectVoices); i++) {
     if (aUri.EqualsASCII(sIndirectVoices[i].uri)) {
       flags = sIndirectVoices[i].flags;
     }
   }
 
+  if (flags & eFailAtStart) {
+    aTask->DispatchError(0, 0);
+    return NS_OK;
+  }
+
   RefPtr<FakeSynthCallback> cb = new FakeSynthCallback(
     (flags & eSuppressEvents) ? nullptr : aTask);
 
   aTask->Setup(cb, 0, 0, 0);
 
   nsCOMPtr<nsIRunnable> runnable = new DispatchStart(aTask);
   NS_DispatchToMainThread(runnable);
 

new file mode 100644
--- /dev/null
+++ b/dom/media/webspeech/synth/test/test_speech_error.html
@@ -0,0 +1,35 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1226015
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1150315: Web Speech API check all classes are present</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript" src="common.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1226015">Mozilla Bug 1226015</a>
+<p id="display"></p>
+<iframe id="testFrame"></iframe>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+<script type="application/javascript">
+
+/** Test for Bug 1226015 **/
+
+SimpleTest.waitForExplicitFinish();
+
+SpecialPowers.pushPrefEnv(
+  { set: [['media.webspeech.synth.enabled', true],
+          ['media.webspeech.synth.force_global_queue', false]] },
+  function() { document.getElementById("testFrame").src = "file_speech_error.html"; });
+
+</script>
+</pre>
+</body>
+</html>