From 29636604453544deb2ffa8ca26e603c48cc9d10c Mon Sep 17 00:00:00 2001
From: Sebastian Hengst <archaeopteryx@coole-files.de>
Date: Tue, 17 May 2016 09:50:29 +0200
Subject: [PATCH] Backed out changeset 14b8c2f4764f (bug 1264694)

---
 dom/media/mediasource/TrackBuffersManager.cpp | 38 +++++++++++++++++++
 dom/media/mediasource/TrackBuffersManager.h   |  5 +--
 2 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/dom/media/mediasource/TrackBuffersManager.cpp b/dom/media/mediasource/TrackBuffersManager.cpp
index a0b251e04291..8353d6af8a0c 100644
--- a/dom/media/mediasource/TrackBuffersManager.cpp
+++ b/dom/media/mediasource/TrackBuffersManager.cpp
@@ -111,6 +111,7 @@ TrackBuffersManager::TrackBuffersManager(MediaSourceDecoder* aParentDecoder,
 
 TrackBuffersManager::~TrackBuffersManager()
 {
+  CancelAllTasks();
   ShutdownDemuxers();
 }
 
@@ -203,6 +204,43 @@ TrackBuffersManager::ProcessTasks()
   GetTaskQueue()->Dispatch(NewRunnableMethod(this, &TrackBuffersManager::ProcessTasks));
 }
 
+// A PromiseHolder will assert upon destruction if it has a pending promise
+// that hasn't been completed. It is possible that a task didn't get processed
+// due to the owning SourceBuffer having shutdown.
+// We resolve/reject all pending promises and remove all pending tasks from the
+// queue.
+void
+TrackBuffersManager::CancelAllTasks()
+{
+  typedef SourceBufferTask::Type Type;
+
+  if (mCurrentTask) {
+    mQueue.Push(mCurrentTask);
+    mCurrentTask = nullptr;
+  }
+
+  RefPtr<SourceBufferTask> task;
+  while ((task = mQueue.Pop())) {
+    switch (task->GetType()) {
+      case Type::AppendBuffer:
+        task->As<AppendBufferTask>()->mPromise.RejectIfExists(NS_ERROR_ABORT, __func__);
+        break;
+      case Type::RangeRemoval:
+        task->As<RangeRemovalTask>()->mPromise.ResolveIfExists(false, __func__);
+        break;
+      case Type::EvictData:
+        break;
+      case Type::Abort:
+        // not handled yet, and probably never.
+        break;
+      case Type::Reset:
+        break;
+      default:
+        NS_WARNING("Invalid Task");
+    }
+  }
+}
+
 // The MSE spec requires that we abort the current SegmentParserLoop
 // which is then followed by a call to ResetParserState.
 // However due to our asynchronous design this causes inherent difficulties.
diff --git a/dom/media/mediasource/TrackBuffersManager.h b/dom/media/mediasource/TrackBuffersManager.h
index 3ab7f3c459ca..fa5194f9fc60 100644
--- a/dom/media/mediasource/TrackBuffersManager.h
+++ b/dom/media/mediasource/TrackBuffersManager.h
@@ -35,10 +35,6 @@ public:
   SourceBufferTaskQueue()
   : mMonitor("SourceBufferTaskQueue")
   {}
-  ~SourceBufferTaskQueue()
-  {
-    MOZ_ASSERT(mQueue.IsEmpty(), "All tasks must have been processed");
-  }
 
   void Push(SourceBufferTask* aTask)
   {
@@ -383,6 +379,7 @@ private:
   // SourceBuffer Queues and running context.
   SourceBufferTaskQueue mQueue;
   void ProcessTasks();
+  void CancelAllTasks();
   // Set if the TrackBuffersManager is currently processing a task.
   // At this stage, this task is always a AppendBufferTask.
   RefPtr<SourceBufferTask> mCurrentTask;