Rename StopWatch to Stopwatch. Add new Stopwatch.start() and Stopwatch.reset().

tests/corelib/src/StopwatchTest.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Dart test program for testing stopwatch support.
 
-class StopWatchTest {
-  static bool checkTicking(StopWatch sw) {
+class StopwatchTest {
+  static bool checkTicking(Stopwatch sw) {
     sw.start();
     for (int i = 0; i < 10000; i++) {
       Math.parseInt(i.toString());
       if (sw.elapsed() > 0) {
         break;
       }
     }
     return sw.elapsed() > 0;
   }
 
-  static bool checkStopping(StopWatch sw) {
+  static bool checkStopping(Stopwatch sw) {
     sw.stop();
     int v1 = sw.elapsed();
     Expect.isTrue(v1 > 0);  // Expect a non-zero elapsed time.
-    StopWatch sw2 = new StopWatch();  // Used for verification.
+    Stopwatch sw2 = new Stopwatch();  // Used for verification.
     sw2.start();
-    for (int i = 0; i < 10000; i++) {
+    int sw2LastElapsed = 0;
+    for (int i = 0; i < 100000; i++) {
       Math.parseInt(i.toString());
       int v2 = sw.elapsed();
       if (v1 != v2) {
         return false;
       }
-      v1 = v2;
+      // If sw2 elapsed twice then sw must have advanced too if it wasn't
+      // stopped.
+      if (sw2LastElapsed > 0 && sw2.elapsed() > sw2LastElapsed) {
+        break;
+      }
+      sw2LastElapsed = sw2.elapsed();
     }
     // The test only makes sense if measureable time elapsed and elapsed time
-    // on the stopped StopWatch did not increase.
+    // on the stopped Stopwatch did not increase.
     Expect.isTrue(sw2.elapsed() > 0);
     return true;
   }
 
   static checkRestart() {
-    StopWatch sw = new StopWatch();
+    Stopwatch sw = new Stopwatch();
     sw.start();
-    for (int i = 0; i < 1000; i++) {
+    for (int i = 0; i < 100000; i++) {
       Math.parseInt(i.toString());
+      if (sw.elapsed() > 0) {
+        break;
+      }
     }
     sw.stop();
     int initial = sw.elapsed();
     sw.start();
-    for (int i = 0; i < 10; i++) {
+    for (int i = 0; i < 100000; i++) {
       Math.parseInt(i.toString());
+      if (sw.elapsed() > initial) {
+        break;
+      }
     }
     sw.stop();
-    Expect.isTrue(sw.elapsed() >= initial);
+    Expect.isTrue(sw.elapsed() > initial);
+  }
+
+  static checkReset() {
+    Stopwatch sw = new Stopwatch();
+    sw.start();
+    for (int i = 0; i < 100000; i++) {
+      Math.parseInt(i.toString());
+      if (sw.elapsed() > 0) {
+        break;
+      }
+    }
+    sw.stop();
+    sw.reset();
+    Expect.equals(0, sw.elapsed());
+    sw.start();
+    for (int i = 0; i < 100000; i++) {
+      Math.parseInt(i.toString());
+      if (sw.elapsed() > 0) {
+        break;
+      }
+    }
+    sw.reset();
+    for (int i = 0; i < 100000; i++) {
+      Math.parseInt(i.toString());
+      if (sw.elapsed() > 0) {
+        break;
+      }
+    }
+    sw.stop();
+    Expect.isTrue(sw.elapsed() > 0);
   }
 
   static testMain() {
-    StopWatch sw = new StopWatch();
+    Stopwatch sw = new Stopwatch();
     Expect.isTrue(checkTicking(sw));
     Expect.isTrue(checkStopping(sw));
     checkRestart();
+    checkReset();
   }
 }
 
 main() {
-  StopWatchTest.testMain();
+  StopwatchTest.testMain();
 }