Remove Stopwatch interface and make it a class.

Review URL: https://codereview.chromium.org//12210065

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@18242 260f80e4-7a28-3924-810f-c04153c831b5

runtime/lib/stopwatch_patch.dart

@@ -4,7 +4,7 @@
 
 // A VM patch of the stopwatch part of dart:core.
 
-patch class _StopwatchImpl {
+patch class Stopwatch {
   // Returns the current clock tick.
   /* patch */ static int _now() native "Stopwatch_now";
 

sdk/lib/_internal/compiler/implementation/lib/core_patch.dart

@@ -158,7 +158,7 @@ patch class DateTime {
 
 
 // Patch for Stopwatch implementation.
-patch class _StopwatchImpl {
+patch class Stopwatch {
   patch static int _frequency() => 1000000;
   patch static int _now() => Primitives.numMicroseconds();
 }

sdk/lib/core/stopwatch.dart

@@ -7,70 +7,7 @@ part of dart.core;
 /**
  * A simple [Stopwatch] interface to measure elapsed time.
  */
-abstract class Stopwatch {
-  /**
-   * Creates a [Stopwatch] in stopped state with a zero elapsed count.
-   *
-   * The following example shows how to start a [Stopwatch]
-   * right after allocation.
-   *
-   *     Stopwatch stopwatch = new Stopwatch()..start();
-   */
-  factory Stopwatch() => new _StopwatchImpl();
-
-  /**
-   * Starts the [Stopwatch]. The [elapsed] count is increasing monotonically.
-   * If the [Stopwatch] has been stopped, then calling start again restarts it
-   * without resetting the [elapsed] count.
-   * If the [Stopwatch] is currently running, then calling start does nothing.
-   */
-  void start();
-
-  /**
-   * Stops the [Stopwatch]. The [elapsed] count stops increasing.
-   * If the [Stopwatch] is currently not running, then calling stop does
-   * nothing.
-   */
-  void stop();
-
-  /**
-   * Resets the [elapsed] count to zero. This method does not stop or start
-   * the [Stopwatch].
-   */
-  void reset();
-
-  /**
-   * Returns the elapsed number of clock ticks since calling [start] while the
-   * [Stopwatch] is running.
-   * Returns the elapsed number of clock ticks between calling [start] and
-   * calling [stop].
-   * Returns 0 if the [Stopwatch] has never been started.
-   * The elapsed number of clock ticks increases by [frequency] every second.
-   */
-  int get elapsedTicks;
-
-  /**
-   * Returns the [elapsedTicks] counter converted to microseconds.
-   */
-  int get elapsedMicroseconds;
-
-  /**
-   * Returns the [elapsedTicks] counter converted to milliseconds.
-   */
-  int get elapsedMilliseconds;
-
-  /**
-   * Returns the frequency of the elapsed counter in Hz.
-   */
-  int get frequency;
-
-  /**
-   * Returns wether the [StopWatch] is currently running.
-   */
-  bool get isRunning;
-}
-
-class _StopwatchImpl implements Stopwatch {
+class Stopwatch {
   // The _start and _stop fields capture the time when [start] and [stop]
   // are called respectively.
   // If _start is null, then the [Stopwatch] has not been started yet.
@@ -79,8 +16,22 @@ class _StopwatchImpl implements Stopwatch {
   int _start;
   int _stop;
 
-  _StopwatchImpl() : _start = null, _stop = null {}
+  /**
+   * Creates a [Stopwatch] in stopped state with a zero elapsed count.
+   *
+   * The following example shows how to start a [Stopwatch]
+   * right after allocation.
+   *
+   *     Stopwatch stopwatch = new Stopwatch()..start();
+   */
+  Stopwatch() : _start = null, _stop = null {}
 
+  /**
+   * Starts the [Stopwatch]. The [elapsed] count is increasing monotonically.
+   * If the [Stopwatch] has been stopped, then calling start again restarts it
+   * without resetting the [elapsed] count.
+   * If the [Stopwatch] is currently running, then calling start does nothing.
+   */
   void start() {
     if (isRunning) return;
     if (_start == null) {
@@ -94,11 +45,20 @@ class _StopwatchImpl implements Stopwatch {
     }
   }
 
+  /**
+   * Stops the [Stopwatch]. The [elapsed] count stops increasing.
+   * If the [Stopwatch] is currently not running, then calling stop does
+   * nothing.
+   */
   void stop() {
     if (!isRunning) return;
     _stop = _now();
   }
 
+  /**
+   * Resets the [elapsed] count to zero. This method does not stop or start
+   * the [Stopwatch].
+   */
   void reset() {
     if (_start == null) return;
     // If [_start] is not null, then the stopwatch had already been started. It
@@ -111,6 +71,14 @@ class _StopwatchImpl implements Stopwatch {
     }
   }
 
+  /**
+   * Returns the elapsed number of clock ticks since calling [start] while the
+   * [Stopwatch] is running.
+   * Returns the elapsed number of clock ticks between calling [start] and
+   * calling [stop].
+   * Returns 0 if the [Stopwatch] has never been started.
+   * The elapsed number of clock ticks increases by [frequency] every second.
+   */
   int get elapsedTicks {
     if (_start == null) {
       return 0;
@@ -118,16 +86,28 @@ class _StopwatchImpl implements Stopwatch {
     return (_stop == null) ? (_now() - _start) : (_stop - _start);
   }
 
+  /**
+   * Returns the [elapsedTicks] counter converted to microseconds.
+   */
   int get elapsedMicroseconds {
     return (elapsedTicks * 1000000) ~/ frequency;
   }
 
+  /**
+   * Returns the [elapsedTicks] counter converted to milliseconds.
+   */
   int get elapsedMilliseconds {
     return (elapsedTicks * 1000) ~/ frequency;
   }
 
+  /**
+   * Returns the frequency of the elapsed counter in Hz.
+   */
   int get frequency => _frequency();
 
+  /**
+   * Returns wether the [StopWatch] is currently running.
+   */
   bool get isRunning => _start != null && _stop == null;
 
   external static int _frequency();