[inspector] fix timestamp formatting with non C locales

src/inspector/string-16.h

Index: src/inspector/string-16.h
diff --git a/src/inspector/string-16.h b/src/inspector/string-16.h
index 94069479579fafaa6cffd3b1b80064914b9a3d3d..457c7479ec51b8b8fcb94fc1361e2bfbb5df595e 100644
--- a/src/inspector/string-16.h
+++ b/src/inspector/string-16.h
@@ -35,6 +35,7 @@ class String16 {
   static String16 fromInteger(int);
   static String16 fromInteger(size_t);
   static String16 fromDouble(double);
+  static String16 fromDoubleForcePointAsSeparator(double);
   static String16 fromDoublePrecision3(double);
   static String16 fromDoublePrecision6(double);