cleanup patch generation to preseve comments and remove @patch

test/generated_sdk/lib/core/uri.dart

Index: test/generated_sdk/lib/core/uri.dart
diff --git a/test/generated_sdk/lib/core/uri.dart b/test/generated_sdk/lib/core/uri.dart
index 37430e95865376455178784b57a546552c79debf..298593fffa71ac879cfdfaaa4bc2e4f54a7fa25a 100644
--- a/test/generated_sdk/lib/core/uri.dart
+++ b/test/generated_sdk/lib/core/uri.dart
@@ -698,14 +698,21 @@ class Uri {
     return windows ? _makeWindowsFileUrl(path) : _makeFileUri(path);
   }
 
-  @patch
+  /**
+   * Returns the natural base URI for the current platform.
+   *
+   * When running in a browser this is the current URL (from
+   * `window.location.href`).
+   *
+   * When not running in a browser this is the file URI referencing
+   * the current working directory.
+   */
   static Uri get base {
     String uri = Primitives.currentUri();
     if (uri != null) return Uri.parse(uri);
     throw new UnsupportedError("'Uri.base' is not supported");
   }
 
-  @patch
   static bool get _isWindows => false;
 
   static _checkNonWindowsPathReservedCharacters(List<String> segments,