Escape all of invalid values in console messages for INPUT elements.

Source/platform/JSONValues.cpp

 /*
  * Copyright (C) 2010 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 70 matching lines @@
 }
 
 void writeIndent(int depth, StringBuilder* output)
 {
     for (int i = 0; i < depth; ++i)
         output->appendLiteral("  ");
 }
 
 } // anonymous namespace
 
+String JSONValue::quoteString(const String& input)
+{
+    StringBuilder builder;
+    doubleQuoteString(input, &builder);
+    return builder.toString();
+}
+
 bool JSONValue::asBoolean(bool*) const
 {
     return false;
 }
 
 bool JSONValue::asNumber(double*) const
 {
     return false;
 }
 
@@ skipping 419 matching lines @@
     m_data.append(value);
 }
 
 PassRefPtr<JSONValue> JSONArrayBase::get(size_t index)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(index < m_data.size());
     return m_data[index];
 }
 
 } // namespace blink