bluetooth: Move writeValue to mojo

content/child/mojo/type_converters.h

Index: content/child/mojo/type_converters.h
diff --git a/content/child/mojo/type_converters.h b/content/child/mojo/type_converters.h
index 180cadb6f5476750a44f2564908cadc0a2598df0..1a9a5bb9527a8e43baf1431210f6781a0dfdfa55 100644
--- a/content/child/mojo/type_converters.h
+++ b/content/child/mojo/type_converters.h
@@ -6,6 +6,7 @@
 #include <utility>
 
 #include "mojo/public/cpp/bindings/array.h"
+#include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 
 namespace mojo {
@@ -20,4 +21,11 @@ struct TypeConverter<Array<T>, blink::WebVector<U>> {
   }
 };
 
+template <>
+struct TypeConverter<String, blink::WebString> {
+  static String Convert(const blink::WebString& web_string) {
+    return String(web_string.utf8());
+  }
+};
+
 }  // namespace mojo