Updates for core/{pattern,regexp,stopwatch,duration}.dart

tool/input_sdk/lib/core/stopwatch.dart

Index: tool/input_sdk/lib/core/stopwatch.dart
diff --git a/tool/input_sdk/lib/core/stopwatch.dart b/tool/input_sdk/lib/core/stopwatch.dart
index 15cd994a913e760a1e2d5a76812f77b572e7af67..e923083a7d174b7d6e611bec9562be51f6579684 100644
--- a/tool/input_sdk/lib/core/stopwatch.dart
+++ b/tool/input_sdk/lib/core/stopwatch.dart
@@ -18,8 +18,8 @@ class Stopwatch {
   // If _start is null, then the [Stopwatch] has not been started yet.
   // If _stop is null, then the [Stopwatch] has not been stopped yet,
   // or is running.
-  num _start;
-  num _stop;
+  int _start;
+  int _stop;
 
   /**
    * Creates a [Stopwatch] in stopped state with a zero elapsed count.