Bug 1144481 - Force state machine setting to go through a setter. r=jww

We need this so that we can hook up the state mirroring in the subsequent patch.

dom/media/MediaDecoder.cpp

@@ -712,8 +712,8 @@ nsresult MediaDecoder::Load(nsIStreamListener** aStreamListener,
   nsresult rv = OpenResource(aStreamListener);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  mDecoderStateMachine = CreateStateMachine();
-  NS_ENSURE_TRUE(mDecoderStateMachine, NS_ERROR_FAILURE);
+  SetStateMachine(CreateStateMachine());
+  NS_ENSURE_TRUE(GetStateMachine(), NS_ERROR_FAILURE);
 
   return InitializeStateMachine(aCloneDonor);
 }
@@ -1596,6 +1596,13 @@ bool MediaDecoder::OnDecodeTaskQueue() const {
   return mDecoderStateMachine ? mDecoderStateMachine->OnDecodeTaskQueue() : false;
 }
 
+void
+MediaDecoder::SetStateMachine(MediaDecoderStateMachine* aStateMachine)
+{
+  MOZ_ASSERT_IF(aStateMachine, !mDecoderStateMachine);
+  mDecoderStateMachine = aStateMachine;
+}
+
 ReentrantMonitor& MediaDecoder::GetReentrantMonitor() {
   return mReentrantMonitor;
 }
@@ -1670,7 +1677,7 @@ bool MediaDecoder::IsShutdown() const {
 
 // Drop reference to state machine.  Only called during shutdown dance.
 void MediaDecoder::BreakCycles() {
-  mDecoderStateMachine = nullptr;
+  SetStateMachine(nullptr);
 }
 
 MediaDecoderOwner* MediaDecoder::GetMediaOwner() const

dom/media/MediaDecoder.h

@@ -680,6 +680,9 @@ public:
 
   bool OnDecodeTaskQueue() const override;
 
+  MediaDecoderStateMachine* GetStateMachine() { return mDecoderStateMachine; }
+  void SetStateMachine(MediaDecoderStateMachine* aStateMachine);
+
   // Returns the monitor for other threads to synchronise access to
   // state.
   ReentrantMonitor& GetReentrantMonitor() override;
@@ -1109,17 +1112,19 @@ protected:
    * The following member variables can be accessed from any thread.
    ******/
 
+  // Media data resource.
+  nsRefPtr<MediaResource> mResource;
+
+private:
   // The state machine object for handling the decoding. It is safe to
   // call methods of this object from other threads. Its internal data
   // is synchronised on a monitor. The lifetime of this object is
   // after mPlayState is LOADING and before mPlayState is SHUTDOWN. It
   // is safe to access it during this period.
+  //
+  // Explicitly prievate to force access via accessors.
   nsRefPtr<MediaDecoderStateMachine> mDecoderStateMachine;
 
-  // Media data resource.
-  nsRefPtr<MediaResource> mResource;
-
-private:
   // |ReentrantMonitor| for detecting when the video play state changes. A call
   // to |Wait| on this monitor will block the thread until the next state
   // change.  Explicitly private for force access via GetReentrantMonitor.

dom/media/mediasource/MediaSourceDecoder.cpp

@@ -54,14 +54,14 @@ MediaSourceDecoder::CreateStateMachine()
 nsresult
 MediaSourceDecoder::Load(nsIStreamListener**, MediaDecoder*)
 {
-  MOZ_ASSERT(!mDecoderStateMachine);
-  mDecoderStateMachine = CreateStateMachine();
-  if (!mDecoderStateMachine) {
+  MOZ_ASSERT(!GetStateMachine());
+  SetStateMachine(CreateStateMachine());
+  if (!GetStateMachine()) {
     NS_WARNING("Failed to create state machine!");
     return NS_ERROR_FAILURE;
   }
 
-  nsresult rv = mDecoderStateMachine->Init(nullptr);
+  nsresult rv = GetStateMachine()->Init(nullptr);
   NS_ENSURE_SUCCESS(rv, rv);
 
   SetStateMachineParameters();
@@ -116,7 +116,7 @@ MediaSourceDecoder::CreateResource(nsIPrincipal* aPrincipal)
 void
 MediaSourceDecoder::AttachMediaSource(dom::MediaSource* aMediaSource)
 {
-  MOZ_ASSERT(!mMediaSource && !mDecoderStateMachine && NS_IsMainThread());
+  MOZ_ASSERT(!mMediaSource && !GetStateMachine() && NS_IsMainThread());
   mMediaSource = aMediaSource;
 }
 
@@ -233,10 +233,10 @@ MediaSourceDecoder::SetMediaSourceDuration(double aDuration, MSRangeRemovalActio
       // We want a very bigger number, but not infinity.
       checkedDuration = INT64_MAX - 1;
     }
-    mDecoderStateMachine->SetDuration(checkedDuration);
+    GetStateMachine()->SetDuration(checkedDuration);
     mMediaSourceDuration = aDuration;
   } else {
-    mDecoderStateMachine->SetDuration(INT64_MAX);
+    GetStateMachine()->SetDuration(INT64_MAX);
     mMediaSourceDuration = PositiveInfinity<double>();
   }
   if (mReader) {

dom/media/omx/MediaOmxCommonDecoder.cpp

@@ -98,16 +98,16 @@ MediaOmxCommonDecoder::PauseStateMachine()
   MOZ_ASSERT(NS_IsMainThread());
   GetReentrantMonitor().AssertCurrentThreadIn();
   DECODER_LOG(PR_LOG_DEBUG, ("%s", __PRETTY_FUNCTION__));
-  if (!mDecoderStateMachine) {
+  if (!GetStateMachine()) {
     return;
   }
   // enter dormant state
   RefPtr<nsRunnable> event =
     NS_NewRunnableMethodWithArg<bool>(
-      mDecoderStateMachine,
+      GetStateMachine(),
       &MediaDecoderStateMachine::SetDormant,
       true);
-  mDecoderStateMachine->TaskQueue()->Dispatch(event);
+  GetStateMachine()->TaskQueue()->Dispatch(event);
 }
 
 void
@@ -118,7 +118,7 @@ MediaOmxCommonDecoder::ResumeStateMachine()
   DECODER_LOG(PR_LOG_DEBUG, ("%s current time %f", __PRETTY_FUNCTION__,
       mCurrentTime));
 
-  if (!mDecoderStateMachine) {
+  if (!GetStateMachine()) {
     return;
   }
 
@@ -134,10 +134,10 @@ MediaOmxCommonDecoder::ResumeStateMachine()
   // exit dormant state
   RefPtr<nsRunnable> event =
     NS_NewRunnableMethodWithArg<bool>(
-      mDecoderStateMachine,
+      GetStateMachine(),
       &MediaDecoderStateMachine::SetDormant,
       false);
-  mDecoderStateMachine->TaskQueue()->Dispatch(event);
+  GetStateMachine()->TaskQueue()->Dispatch(event);
 }
 
 void