bug 525573: in --enable-tracemalloc builds, initialize tracemalloc in XPCOM unit tests so as to support multi-threaded tests. r=jwalden

xpcom/tests/TestHarness.h

@@ -59,6 +59,10 @@
 #include <stdlib.h>
 #include <stdarg.h>
 
+#ifdef NS_TRACE_MALLOC
+#  include "nsTraceMalloc.h"
+#endif
+
 static PRUint32 gFailCount = 0;
 
 /**
@@ -247,6 +251,11 @@ class ScopedXPCOM : public nsIDirectoryServiceProvider2
       mTestName = testName;
       printf("Running %s tests...\n", mTestName);
 
+#ifdef NS_TRACE_MALLOC
+      // nsAppRunner starts tracemalloc before init'ing XPCOM
+      NS_TraceMallocStartup(-1); // -1 == no logging
+#endif
+
       nsresult rv = NS_InitXPCOM2(&mServMgr, NULL, this);
       if (NS_FAILED(rv))
       {