Revert of Stop doing unnecessary UTF-8 to UTF-16 conversions in JSONWriter.

chrome/test/chromedriver/capabilities.cc

Index: chrome/test/chromedriver/capabilities.cc
diff --git a/chrome/test/chromedriver/capabilities.cc b/chrome/test/chromedriver/capabilities.cc
index 092855ced8ef5107fb9f2bd41abe3aa0e5ebc894..6e884c907d31bef0c4d9f7d36f67083df97822c8 100644
--- a/chrome/test/chromedriver/capabilities.cc
+++ b/chrome/test/chromedriver/capabilities.cc
@@ -393,7 +393,7 @@
     std::string value = GetSwitchValue(iter->first);
     if (value.length()) {
       if (value.find(' ') != std::string::npos)
-        value = base::GetQuotedJSONString(value);
+        value = base::GetDoubleQuotedJson(value);
       str += "=" + value;
     }
     ++iter;