Get rid of unnecessary calls to toDouble().

pkg/analysis_server/test/integration/integration_tests.dart

Index: pkg/analysis_server/test/integration/integration_tests.dart
diff --git a/pkg/analysis_server/test/integration/integration_tests.dart b/pkg/analysis_server/test/integration/integration_tests.dart
index 59c3f321a5f32be02fd6c197d3bb1aebbc83dbca..f2e4b2b7e78caaa93efd9cd6be25348e2692738e 100644
--- a/pkg/analysis_server/test/integration/integration_tests.dart
+++ b/pkg/analysis_server/test/integration/integration_tests.dart
@@ -715,8 +715,7 @@ class Server {
    * [debugStdio] has been called.
    */
   void _recordStdio(String line) {
-    double elapsedTime = _time.elapsedTicks.toDouble() /
-        _time.frequency.toDouble();
+    double elapsedTime = _time.elapsedTicks / _time.frequency;
     line = "$elapsedTime: $line";
     if (_debuggingStdio) {
       print(line);