Bug#81373 (mac static build)

added static_build option
r=jfrancis
sr=sfraser
a=asa on behalf of drivers

build/mac/build_scripts/MozillaBuildFlags.txt

@@ -68,7 +68,7 @@ xml_rpc         1
 cview           1
 help            1
 timeline        0      MOZ_TIMELINE
-
+static_build    0      MOZ_STATIC_COMPONENT_LIBS
 string_debug    0      DEBUG_STRING
 string_stats    0      DEBUG_STRING_STATS