Fix for compiler error:

src\core\skdata.cpp(126) : fatal error C1017: invalid integer constant expression



git-svn-id: http://skia.googlecode.com/svn/trunk@8849 2bbb7eff-a529-9590-31e7-b0007b416f81

src/core/SkData.cpp

@@ -123,7 +123,7 @@ SkData* SkData::NewFromFILE(SkFILE* f) {
     return SkData::NewWithProc(addr, size, sk_munmap_releaseproc, NULL);
 }
 
-#elif SK_BUILD_FOR_WIN32
+#elif defined(SK_BUILD_FOR_WIN32)
 
 template <typename HandleType, HandleType InvalidValue, BOOL (WINAPI * Close)(HandleType)>
 class SkAutoTHandle : SkNoncopyable {