[inspector] fix timestamp formatting with non C locales

src/inspector/string-16.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INSPECTOR_STRING16_H_
 #define V8_INSPECTOR_STRING16_H_
 
 #include <stdint.h>
 #include <cctype>
 #include <climits>
@@ skipping 17 matching lines @@
   String16(const char* characters)  // NOLINT(runtime/explicit)
       : String16(characters, std::strlen(characters)) {}
   String16(const char* characters, size_t size) {
     m_impl.resize(size);
     for (size_t i = 0; i < size; ++i) m_impl[i] = characters[i];
   }
 
   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);
 
   int toInteger(bool* ok = nullptr) const;
   String16 stripWhiteSpace() const;
   const UChar* characters16() const { return m_impl.c_str(); }
   size_t length() const { return m_impl.length(); }
   bool isEmpty() const { return !m_impl.length(); }
   UChar operator[](size_t index) const { return m_impl[index]; }
   String16 substring(size_t pos, size_t len = UINT_MAX) const {
@@ skipping 77 matching lines @@
   std::size_t operator()(const v8_inspector::String16& string) const {
     return string.hash();
   }
 };
 
 }  // namespace std
 
 #endif  // !defined(__APPLE__) || defined(_LIBCPP_VERSION)
 
 #endif  // V8_INSPECTOR_STRING16_H_