cleanup patch generation to preseve comments and remove @patch

test/generated_sdk/lib/convert/json.dart

Index: test/generated_sdk/lib/convert/json.dart
diff --git a/test/generated_sdk/lib/convert/json.dart b/test/generated_sdk/lib/convert/json.dart
index 657dff0980eb2ff61f3a5ccf4ce6aa6b8b66c217..3f3596762d5f9b7cfc439c8dd6329243bfe0c61e 100644
--- a/test/generated_sdk/lib/convert/json.dart
+++ b/test/generated_sdk/lib/convert/json.dart
@@ -495,7 +495,12 @@ class JsonDecoder extends Converter<String, Object> {
    */
   dynamic convert(String input) => _parseJson(input, _reviver);
 
-  @patch
+  /**
+   * Starts a conversion from a chunked JSON string to its corresponding
+   * object.
+   *
+   * The output [sink] receives exactly one decoded element through `add`.
+   */
   StringConversionSink startChunkedConversion(Sink<Object> sink) {
     return new _JsonDecoderSink(_reviver, sink);
   }
@@ -505,23 +510,6 @@ class JsonDecoder extends Converter<String, Object> {
 }
 
 // Internal optimized JSON parsing implementation.
-/**
- * Parses [json] and builds the corresponding parsed JSON value.
- *
- * Parsed JSON values Nare of the types [num], [String], [bool], [Null],
- * [List]s of parsed JSON values or [Map]s from [String] to parsed
- * JSON values.
- *
- * The optional [reviver] function, if provided, is called once for each object
- * or list property parsed. The arguments are the property name ([String]) or
- * list index ([int]), and the value is the parsed value.  The return value of
- * the reviver will be used as the value of that property instead of the parsed
- * value.  The top level value is passed to the reviver with the empty string as
- * a key.
- *
- * Throws [FormatException] if the input is not valid JSON text.
- */
-@patch
 _parseJson(String source, reviver(key, value)) {
   if (source is! String) throw new ArgumentError(source);