Backed out changeset 7785b40af14f for landing with the wrong bug numb…

…er in the commit message.

media/libpng/moz.build

@@ -27,7 +27,7 @@ UNIFIED_SOURCES += [
     'pngwutil.c'
 ]
 
-if CONFIG['CPU_ARCH'] == 'arm':
+if CONFIG['MOZ_PNG_ARM_NEON']:
     DEFINES['MOZ_PNG_HAVE_ARM_NEON'] = True
     UNIFIED_SOURCES += [
         'arm/arm_init.c',

old-configure.in

@@ -2207,6 +2207,8 @@ if test "$MOZ_LINKER" = 1 -a "$MOZ_SYSTEM_ZLIB" != 1; then
     AC_MSG_ERROR([Custom dynamic linker requires --with-system-zlib])
 fi
 
+MOZ_PNG_ARM_NEON=
+
 if test -z "$SKIP_LIBRARY_CHECKS"; then
 dnl system BZIP2 Support
 dnl ========================================================
@@ -2282,8 +2284,32 @@ if test "${PNG_DIR}" -a -d "${PNG_DIR}" -a "$MOZ_SYSTEM_PNG" = 1; then
     MOZ_PNG_LIBS="-L${PNG_DIR}/lib ${MOZ_PNG_LIBS}"
 fi
 
+if test "$MOZ_SYSTEM_PNG" != 1 -a "$CPU_ARCH" = "arm" ; then
+    MOZ_ARG_ENABLE_STRING(png-arm-neon-support,
+        [  --enable-png-arm-neon-support=TYPE
+             Options include:
+                 no
+                 check (default)
+                 nocheck (faster but unsafe)],
+        [MOZ_PNG_ARM_NEON_SUPPORT=$enableval ] )
+    case "$MOZ_PNG_ARM_NEON_SUPPORT" in
+        no)
+            # enable-png-arm-neon-support = no
+            ;;
+        nocheck)
+            # enable-png-arm-neon-support = nocheck
+            MOZ_PNG_ARM_NEON=1
+            ;;
+        *)
+            MOZ_PNG_ARM_NEON=1
+            ;;
+    esac
+fi
+
 fi # SKIP_LIBRARY_CHECKS
 
+AC_SUBST(MOZ_PNG_ARM_NEON)
+
 dnl ========================================================
 dnl =
 dnl = Application