Bug 1407063 - Fix non-unified build in MoofParser.cpp. r=gerald

The stagefright namespace isn't used in this file and because it
wasn't previously declared in this compilation unit, a compiler error was raised.

MozReview-Commit-ID: HoYyrmIIXSV

--HG--
extra : rebase_source : 57ac59c06cdc4f54676c86a109ae404072541555

media/libstagefright/binding/MoofParser.cpp

@@ -24,7 +24,6 @@ extern mozilla::LogModule* GetDemuxerLog();
 namespace mp4_demuxer
 {
 
-using namespace stagefright;
 using namespace mozilla;
 
 const uint32_t kKeyIdSize = 16;