From 32d2d557d712200fd160e91d03915f7d4866412f Mon Sep 17 00:00:00 2001
From: JW Wang <jwwang@mozilla.com>
Date: Mon, 2 Nov 2015 21:26:12 +0800
Subject: [PATCH] Bug 1139256 - remove the assertion in
 AudioStream::GetPositionInFramesUnlocked(). See bug 1139256 comment 4 for the
 detail. r=kinetik.

---
 dom/media/AudioStream.cpp                    | 8 +-------
 dom/media/AudioStream.h                      | 3 ---
 dom/media/mediasink/DecodedAudioDataSink.cpp | 6 +++++-
 3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/dom/media/AudioStream.cpp b/dom/media/AudioStream.cpp
index 4a93b25978a0..2277b37b5cd5 100644
--- a/dom/media/AudioStream.cpp
+++ b/dom/media/AudioStream.cpp
@@ -130,7 +130,6 @@ AudioStream::AudioStream()
   , mDumpFile(nullptr)
   , mBytesPerFrame(0)
   , mState(INITIALIZED)
-  , mLastGoodPosition(0)
   , mIsMonoAudioEnabled(gfxPrefs::MonoAudio())
 {
 }
@@ -622,12 +621,7 @@ AudioStream::GetPositionInFramesUnlocked()
     }
   }
 
-  MOZ_ASSERT(position >= mLastGoodPosition, "cubeb position shouldn't go backward");
-  // This error handling/recovery keeps us in good shape in release build.
-  if (position >= mLastGoodPosition) {
-    mLastGoodPosition = position;
-  }
-  return std::min<uint64_t>(mLastGoodPosition, INT64_MAX);
+  return std::min<uint64_t>(position, INT64_MAX);
 }
 
 bool
diff --git a/dom/media/AudioStream.h b/dom/media/AudioStream.h
index e444540ff9ab..dc84feaf63bd 100644
--- a/dom/media/AudioStream.h
+++ b/dom/media/AudioStream.h
@@ -322,9 +322,6 @@ private:
 
   StreamState mState;
   bool mIsFirst;
-  // The last good position returned by cubeb_stream_get_position(). Used to
-  // check if the cubeb position is going backward.
-  uint64_t mLastGoodPosition;
   // Get this value from the preferece, if true, we would downmix the stereo.
   bool mIsMonoAudioEnabled;
 };
diff --git a/dom/media/mediasink/DecodedAudioDataSink.cpp b/dom/media/mediasink/DecodedAudioDataSink.cpp
index 166f39c3b639..9953fb2ebefe 100644
--- a/dom/media/mediasink/DecodedAudioDataSink.cpp
+++ b/dom/media/mediasink/DecodedAudioDataSink.cpp
@@ -143,8 +143,12 @@ DecodedAudioDataSink::GetPosition()
   int64_t pos;
   if (mAudioStream &&
       (pos = mAudioStream->GetPosition()) >= 0) {
+    NS_ASSERTION(pos >= mLastGoodPosition,
+                 "AudioStream position shouldn't go backward");
     // Update the last good position when we got a good one.
-    mLastGoodPosition = pos;
+    if (pos >= mLastGoodPosition) {
+      mLastGoodPosition = pos;
+    }
   }
 
   return mStartTime + mLastGoodPosition;