Revert revisions 36163 and 36162

tools/testing/dart/test_suite.dart

Index: tools/testing/dart/test_suite.dart
===================================================================
--- tools/testing/dart/test_suite.dart	(revision 36164)
+++ tools/testing/dart/test_suite.dart	(working copy)
@@ -1917,23 +1917,6 @@
         .pipe(new File(dest.toNativePath()).openWrite());
   }
 
-  static Future isContentEqual(Path source, Path dest) {
-    return new File(source.toNativePath()).readAsString()
-      .then((srcString) {
-        return new File(dest.toNativePath()).readAsString()
-          .then((destString) => srcString == destString);
-      })
-      .catchError((error) {
-          return false;
-      });
-  }
-
-  static Future copyIfDifferent(Path source, Path dest) {
-    return isContentEqual(source, dest).then((equal) {
-      return equal ? null : TestUtils.copyFile(source, dest);
-    });
-  }
-
   static Future copyDirectory(String source, String dest) {
     source = new Path(source).toNativePath();
     dest = new Path(dest).toNativePath();
@@ -2164,11 +2147,6 @@
     }
     return path;
   }
-
-  static String cachedOutputFile(String outputFile) {
-    return "$outputFile.cached_output";
-  }
-
 }
 
 class SummaryReport {