clang/win: Fix another -Wunused-local-typedef warning.

chrome/installer/mini_installer/mini_string.h

Index: chrome/installer/mini_installer/mini_string.h
diff --git a/chrome/installer/mini_installer/mini_string.h b/chrome/installer/mini_installer/mini_string.h
index 199c694369bd0ad4e243aeda41976b3c3b941795..52833a8087b897905b21a6cf6cc8287cc00ddfd4 100644
--- a/chrome/installer/mini_installer/mini_string.h
+++ b/chrome/installer/mini_installer/mini_string.h
@@ -6,11 +6,8 @@
 #define CHROME_INSTALLER_MINI_INSTALLER_MINI_STRING_H_
 
 #ifndef COMPILE_ASSERT
-// COMPILE_ASSERT macro borrowed from basictypes.h
-template <bool>
-struct CompileAssert {};
-#define COMPILE_ASSERT(expr, msg) \
-    typedef CompileAssert<(bool(expr))> msg[bool(expr) ? 1 : -1]
+// COMPILE_ASSERT macro borrowed from macros.h
+#define COMPILE_ASSERT(expr, msg) static_assert(expr, #msg)
 #endif
 
 namespace mini_installer {