Bug 599567: Followup to make new checks conditioned on COMPILE_ENVIRONMENT too. r=me a=me

configure.in

@@ -6001,9 +6001,9 @@ if test -n "$MOZ_WEBM"; then
     WINNT:x86)
       if test -z "$GNU_CC"; then
         dnl Check for yasm 1.1 or greater.
-        if test -z "$YASM"; then
+        if test -n "$COMPILE_ENVIRONMENT" -a -z "$YASM"; then
           AC_MSG_ERROR([yasm 1.1 or greater is required to build libvpx on Win32, but it appears not to be installed.  Install it (included in MozillaBuild 1.5.1 and newer) or configure with --disable-webm (which disables the WebM video format). See https://developer.mozilla.org/en/YASM for more details.])
-        elif test "$_YASM_MAJOR_VERSION" -lt "1" -o \( "$_YASM_MAJOR_VERSION" -eq "1" -a "$_YASM_MINOR_VERSION" -lt "1" \) ; then
+        elif test -n "$COMPILE_ENVIRONMENT" -a "$_YASM_MAJOR_VERSION" -lt "1" -o \( "$_YASM_MAJOR_VERSION" -eq "1" -a "$_YASM_MINOR_VERSION" -lt "1" \) ; then
           AC_MSG_ERROR([yasm 1.1 or greater is required to build libvpx on Win32, but you appear to have version $_YASM_MAJOR_VERSION.$_YASM_MINOR_VERSION.  Upgrade to the newest version (included in MozillaBuild 1.5.1 and newer) or configure with --disable-webm (which disables the WebM video format). See https://developer.mozilla.org/en/YASM for more details.])
         else
           VPX_ASFLAGS="-f win32 -rnasm -pnasm -DPIC"