Add explicit conversions methods for WebString <-> string16

third_party/WebKit/Source/platform/exported/WebString.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 63 matching lines @@
 }
 
 WebString WebString::fromUTF8(const char* data, size_t length) {
   return String::fromUTF8(data, length);
 }
 
 WebString WebString::fromUTF8(const char* data) {
   return String::fromUTF8(data);
 }
 
+WebString WebString::fromUTF16(const base::string16& s) {
+  WebString string;
+  string.assign(s.data(), s.length());
+  return string;
+}
+
+WebString WebString::fromUTF16(const base::NullableString16& s) {
+  WebString string;
+  if (s.is_null())
+    string.reset();
+  else
+    string.assign(s.string().data(), s.string().length());
+  return string;
+}
+
 std::string WebString::latin1() const {
   String string(m_private.get());
 
   if (string.isEmpty())
     return std::string();
 
   if (string.is8Bit())
     return std::string(reinterpret_cast<const char*>(string.characters8()),
                        string.length());
 
@@ skipping 63 matching lines @@
 
 WebString::operator WTF::AtomicString() const {
   return WTF::AtomicString(m_private.get());
 }
 
 void WebString::assign(WTF::StringImpl* p) {
   m_private = p;
 }
 
 }  // namespace blink