Bug 1475701 - Save Page As doesn't begin MP3 download while tab is open, r=valentin

We need to close the cache entry if opening output stream for writing/appending data failed, so the entry isn't blocked for other requests.

netwerk/protocol/http/nsHttpChannel.cpp

@@ -5421,6 +5421,7 @@ nsHttpChannel::InstallCacheListener(int64_t offset)
     }
     if (rv == NS_ERROR_FILE_TOO_BIG) {
         LOG(("  entry would exceed max allowed size, not writing it [channel=%p]", this));
+        CloseCacheEntry(false);
         return NS_OK;
     }
     if (NS_FAILED(rv)) return rv;