Refactor Timer to meet newly published dart style guidelines

[DartBot]

This issue was originally filed by @chrisbu

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>What steps will reproduce the problem?

The dart style guide reads:
"AVOID boolean arguments unless their meaning is completely obvious."

Reading the SocketSample.dart example, I had to dig around the timer.dart source to find out what the "timer" part of the code did as it doesn't meet this style.

dart/runtime/bin/timer.dart

The timer defined as:
Timer(void callback(Timer timer), int milliSeconds, bool repeating);

Reads like this when used:

new Timer((t) {}, 1000, true)

and I initially read the "true" as reading "Start the timer" (rather than wait for me to call start() or some such method).

It was only when I found the interface doc that I realised that I was wrong in that assumption.

>What is the expected output? What do you see instead?

I would expect timer constructors such as

Timer.repeating(callback, ms)
and
Timer(callback, ms)

Cheers,
Chris Buckett.

[DartBot]

This comment was originally written by drfibonacci@google.com

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Removed Type-Defect label.
Added Type-Enhancement, Area-Library, Triaged labels.

[DartBot]

This comment was originally written by drfibonacci@google.com

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Added Duplicate label.
Marked as being merged into #340.

[DartBot]

This comment was originally written by mattsh@google.com

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(I'm reopening, because issues 340 is quite general, but I think it's better to have an issue specifically for what constructors the Timer class should have.)

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Added Triaged label.
Marked as being merged into #.

[madsager]

I changed the Timer interface by adding a named constructor.

new Timer(action, ms);
new Timer.repeating(action, ms);

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Set owner to @madsager.
Added Fixed label.