Bug 1415766. P2 - move Seek() to private and tighten up some assertions. r=bechen,gerald

MozReview-Commit-ID: BBsXqKUrOi1

--HG--
extra : rebase_source : 1b785f50254ba824037b983896fc40e91eff801a
extra : intermediate-source : 6971ed66e78c4e1956bf0e382a04c1c8816dbaf8
extra : source : 6590c3f4691e9730858689839a5eb7b7143ceafb

dom/media/MediaCache.cpp

@@ -2415,18 +2415,18 @@ MediaCacheStream::SetPlaybackRate(uint32_t aBytesPerSecond)
 nsresult
 MediaCacheStream::Seek(int64_t aOffset)
 {
-  NS_ASSERTION(!NS_IsMainThread(), "Don't call on main thread");
+  MOZ_ASSERT(!NS_IsMainThread());
+  mMediaCache->GetReentrantMonitor().AssertCurrentThreadIn();
 
-  ReentrantMonitorAutoEnter mon(mMediaCache->GetReentrantMonitor());
+  if (!IsOffsetAllowed(aOffset)) {
+    return NS_ERROR_ILLEGAL_VALUE;
+  }
   if (mClosed) {
-    return NS_ERROR_FAILURE;
+    return NS_ERROR_ABORT;
   }
+
   int64_t oldOffset = mStreamOffset;
-  int64_t newOffset = aOffset;
-  if (!IsOffsetAllowed(newOffset)) {
-    return NS_ERROR_FAILURE;
-  }
-  mStreamOffset = newOffset;
+  mStreamOffset = aOffset;
   LOG("Stream %p Seek to %" PRId64, this, mStreamOffset);
   mMediaCache->NoteSeek(this, oldOffset);
   mMediaCache->QueueUpdate();

dom/media/MediaCache.h

@@ -339,7 +339,6 @@ public:
   // These methods must be called on a different thread from the main
   // thread. They should always be called on the same thread for a given
   // stream.
-  nsresult Seek(int64_t aOffset);
   int64_t Tell();
   // *aBytes gets the number of bytes that were actually read. This can
   // be less than aCount. If the first byte of data is not in the cache,
@@ -433,6 +432,9 @@ private:
   Result<uint32_t, nsresult> ReadBlockFromCache(int64_t aOffset,
                                                 Span<char> aBuffer);
 
+  // Non-main thread only.
+  nsresult Seek(int64_t aOffset);
+
   // Returns the end of the bytes starting at the given offset
   // which are in cache.
   // This method assumes that the cache monitor is held and can be called on