Add optional schema compiler error messages

tools/json_schema_compiler/util.cc

Index: tools/json_schema_compiler/util.cc
diff --git a/tools/json_schema_compiler/util.cc b/tools/json_schema_compiler/util.cc
index 25f908cf2af0537b6c328af66c450833fde04732..03cb517b9d8c6015db1fda739ef10dd2a400d957 100644
--- a/tools/json_schema_compiler/util.cc
+++ b/tools/json_schema_compiler/util.cc
@@ -70,5 +70,39 @@ void AddItemToList(const linked_ptr<base::DictionaryValue>& from,
   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