Ignore unknown attributes when parsing JSON schemas.

components/json_schema/json_schema_validator.h

Index: components/json_schema/json_schema_validator.h
diff --git a/components/json_schema/json_schema_validator.h b/components/json_schema/json_schema_validator.h
index 4584a9da77a5be1bf1b17d5babebc46133b3b913..4e8acaddfd983c68b10c02f126e29b6a498cc2ab 100644
--- a/components/json_schema/json_schema_validator.h
+++ b/components/json_schema/json_schema_validator.h
@@ -70,6 +70,12 @@ class JSONSchemaValidator {
     std::string message;
   };
 
+  enum Options {
+    // Ignore unknown attributes. If this option is not set then unknown
+    // attributes will make the schema validation fail.
+    OPTIONS_IGNORE_UNKNOWN_ATTRIBUTES = 1 << 0,
+  };
+
   // Error messages.
   static const char kUnknownTypeReference[];
   static const char kInvalidChoice[];
@@ -108,6 +114,13 @@ class JSONSchemaValidator {
       const std::string& schema,
       std::string* error);
 
+  // Same as above but with |options|, which is a bitwise-OR combination of the
+  // Options above.
+  static scoped_ptr<base::DictionaryValue> IsValidSchema(
+      const std::string& schema,
+      int options,
+      std::string* error);
+
   // Creates a validator for the specified schema.
   //
   // NOTE: This constructor assumes that |schema| is well formed and valid.