Bug 1398659. P1 - tighten up the assertions in InitAsClone(). r=gerald

We also make it return void since it now always succeeds.

MozReview-Commit-ID: H1oQWoguEzF

--HG--
extra : rebase_source : b5c6714832bed6fceb80c4afcdf4a590cc7dc567
extra : intermediate-source : 01aa9da848391bbf0b39f8dca874c0234f3202fb
extra : source : af04510d8603ffe407069ef342fdb4d3bca33509

dom/media/MediaCache.cpp

@@ -2561,17 +2561,13 @@ MediaCacheStream::Init(int64_t aContentLength)
   return NS_OK;
 }
 
-nsresult
+void
 MediaCacheStream::InitAsClone(MediaCacheStream* aOriginal)
 {
-  if (!aOriginal->IsAvailableForSharing())
-    return NS_ERROR_FAILURE;
+  MOZ_ASSERT(aOriginal->IsAvailableForSharing());
+  MOZ_ASSERT(!mMediaCache, "Has been initialized.");
+  MOZ_ASSERT(aOriginal->mMediaCache, "Don't clone an uninitialized stream.");
 
-  if (mMediaCache) {
-    return NS_OK;
-  }
-
-  NS_ASSERTION(aOriginal->mMediaCache, "Don't clone an uninitialized stream");
   // Use the same MediaCache as our clone.
   mMediaCache = aOriginal->mMediaCache;
 
@@ -2609,8 +2605,6 @@ MediaCacheStream::InitAsClone(MediaCacheStream* aOriginal)
     // stream offset is zero
     mMediaCache->AddBlockOwnerAsReadahead(cacheBlockIndex, this, i);
   }
-
-  return NS_OK;
 }
 
 nsresult MediaCacheStream::GetCachedRanges(MediaByteRangeSet& aRanges)

dom/media/MediaCache.h

@@ -205,10 +205,10 @@ public:
   nsresult Init(int64_t aContentLength);
 
   // Set up this stream with the cache, assuming it's for the same data
-  // as the aOriginal stream. Can fail on OOM.
+  // as the aOriginal stream.
   // Exactly one of InitAsClone or Init must be called before any other method
-  // on this class. Does nothing if already initialized.
-  nsresult InitAsClone(MediaCacheStream* aOriginal);
+  // on this class.
+  void InitAsClone(MediaCacheStream* aOriginal);
 
   // These are called on the main thread.
   // Tell us whether the stream is seekable or not. Non-seekable streams