Minor doc improvements. (#13969)

packages/flutter/lib/src/animation/animation_controller.dart

@@ -211,6 +211,15 @@ class AnimationController extends Animation<double>
   /// The most recently returned [TickerFuture], if any, is marked as having been
   /// canceled, meaning the future never completes and its [TickerFuture.orCancel]
   /// derivative future completes with a [TickerCanceled] error.
+  ///
+  /// See also:
+  ///
+  ///  * [reset], which is equivalent to setting [value] to [lowerBound].
+  ///  * [stop], which aborts the animation without changing its value or status
+  ///    and without dispatching any notifications other than completing or
+  ///    canceling the [TickerFuture].
+  ///  * [forward], [reverse], [animateTo], [animateWith], [fling], and [repeat],
+  ///    which start the animation controller.
   set value(double newValue) {
     assert(newValue != null);
     stop();
@@ -221,6 +230,18 @@ class AnimationController extends Animation<double>
   
   /// Sets the controller's value to [lowerBound], stopping the animation (if
   /// in progress), and resetting to its beginning point, or dismissed state.
+  ///
+  /// The most recently returned [TickerFuture], if any, is marked as having been
+  /// canceled, meaning the future never completes and its [TickerFuture.orCancel]
+  /// derivative future completes with a [TickerCanceled] error.
+  ///
+  /// See also:
+  ///
+  ///  * [value], which can be explicitly set to a specific value as desired.
+  ///  * [forward], which starts the animation in the forward direction.
+  ///  * [stop], which aborts the animation without changing its value or status
+  ///    and without dispatching any notifications other than completing or
+  ///    canceling the [TickerFuture].
   void reset() {
     value = lowerBound;
   }
@@ -463,8 +484,15 @@ class AnimationController extends Animation<double>
   /// By default, the most recently returned [TickerFuture] is marked as having
   /// been canceled, meaning the future never completes and its
   /// [TickerFuture.orCancel] derivative future completes with a [TickerCanceled]
-  /// error. By passing the `completed` argument with the value false, this is
+  /// error. By passing the `canceled` argument with the value false, this is
   /// reversed, and the futures complete successfully.
+  ///
+  /// See also:
+  ///
+  ///  * [reset], which stops the animation and resets it to the [lowerBound],
+  ///    and which does send notifications.
+  ///  * [forward], [reverse], [animateTo], [animateWith], [fling], and [repeat],
+  ///    which restart the animation controller.
   void stop({ bool canceled: true }) {
     _simulation = null;
     _lastElapsedDuration = null;

packages/flutter/lib/src/scheduler/ticker.dart

@@ -346,7 +346,7 @@ class Ticker {
 /// if the [Ticker] that returned the [TickerFuture] was stopped with `canceled`
 /// set to true, or if it was disposed without being stopped.
 ///
-/// To run a callback when either this future resolves or when the tricker is
+/// To run a callback when either this future resolves or when the ticker is
 /// canceled, use [whenCompleteOrCancel].
 class TickerFuture implements Future<Null> {
   TickerFuture._();
@@ -381,6 +381,10 @@ class TickerFuture implements Future<Null> {
 
   /// Calls `callback` either when this future resolves or when the ticker is
   /// canceled.
+  ///
+  /// Calling this method registers an exception handler for the [orCancel]
+  /// future, so even if the [orCancel] property is accessed, canceling the
+  /// ticker will not cause an uncaught exception in the current zone.
   void whenCompleteOrCancel(VoidCallback callback) {
     Null thunk(dynamic value) {
       callback();
@@ -391,6 +395,12 @@ class TickerFuture implements Future<Null> {
 
   /// A future that resolves when this future resolves or throws when the ticker
   /// is canceled.
+  ///
+  /// If this property is never accessed, then canceling the ticker does not
+  /// throw any exceptions. Once this property is accessed, though, if the
+  /// corresponding ticker is canceled, then the [Future] returned by this
+  /// getter will complete with an error, and if that error is not caught, there
+  /// will be an uncaught exception in the current zone.
   Future<Null> get orCancel {
     if (_secondaryCompleter == null) {
       _secondaryCompleter = new Completer<Null>();
@@ -443,7 +453,7 @@ class TickerCanceled implements Exception {
   /// Reference to the [Ticker] object that was canceled.
   ///
   /// This may be null in the case that the [Future] created for
-  /// [TickerFuture.orCancel] was created after the future was canceled.
+  /// [TickerFuture.orCancel] was created after the ticker was canceled.
   final Ticker ticker;
 
   @override