bug 1394341 replace xmalloc with operator new(size_t) to match AudioBlock deallocation in delete r=padenot

MozReview-Commit-ID: EqDe41PBf3C

--HG--
extra : rebase_source : e88f0ae221e1d5985e292f891ab033d5a048ea72

dom/media/webaudio/AudioBlock.cpp

@@ -43,7 +43,7 @@ public:
       MOZ_CRASH();
     }
 
-    void* m = moz_xmalloc(size.value());
+    void* m = operator new(size.value());
     RefPtr<AudioBlockBuffer> p = new (m) AudioBlockBuffer();
     NS_ASSERTION((reinterpret_cast<char*>(p.get() + 1) - reinterpret_cast<char*>(p.get())) % 4 == 0,
                  "AudioBlockBuffers should be at least 4-byte aligned");