Add optional schema compiler error messages

tools/json_schema_compiler/util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/json_schema_compiler/util.h"
 
 #include "base/values.h"
 
 namespace json_schema_compiler {
 namespace util {
@@ skipping 52 matching lines @@
 void AddItemToList(const linked_ptr<base::Value>& from,
                    base::ListValue* out) {
   out->Append(from->DeepCopy());
 }
 
 void AddItemToList(const linked_ptr<base::DictionaryValue>& from,
                    base::ListValue* out) {
   out->Append(static_cast<Value*>(from->DeepCopy()));
 }
 
+std::string ValueTypeToString(Value::Type type) {
+  std::string out;
+  switch(type) {
+    case Value::TYPE_NULL:
+      out = "null";
+      break;
+    case Value::TYPE_BOOLEAN:
+      out = "boolean";
+      break;
+    case Value::TYPE_INTEGER:
+      out = "int";
+      break;
+    case Value::TYPE_DOUBLE:
+      out = "double";
+      break;
+    case Value::TYPE_STRING:
+      out = "std::string";

[not at google - send to devlin, 2013/06/14 21:48:39]

just "string"

[Aaron Jacobs, 2013/06/15 00:47:18]

Done.

+      break;
+    case Value::TYPE_BINARY:
+      out = "binary";
+      break;
+    case Value::TYPE_DICTIONARY:
+      out = "dictionary";
+      break;
+    case Value::TYPE_LIST:
+      out = "list";
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  return out;
+}

[not at google - send to devlin, 2013/06/14 21:48:39]

1. this can be a lot shorter if you just have 'return "null"' rather than
assigning to |out|.
2. leave out the default case so that the compiler catches errors. instead, have
NOTREACHED at the end and return ""

[Aaron Jacobs, 2013/06/15 00:47:18]

Done.

+
 }  // namespace api_util
 }  // namespace extensions