Revert watcher changes for mac.

Revert watcher changes for mac.

We ended up with a 1.6 dependency, which I don't know if is a good idea or not.

Revert "Mac no longer fire bogus events. Fix Mac watcher."
Revert "Don't use kFSEventStreamCreateFlagNoDefer as it messes with event flushing."

BUG=

Committed: https://code.google.com/p/dart/source/detail?r=37173

[Anders Johnsen, 2014-06-10 12:35:40]

Note that this does _NOT_ revert the actual fix to the SDK.

[Anders Johnsen, 2014-06-10 12:35:48]

TBR

[Anders Johnsen, 2014-06-10 12:36:03]

Committed patchset #2 manually as r37173 (presubmit successful).

[Søren Gjesse, 2014-06-10 12:45:27]

lgtm

[kevmoo, 2014-06-10 18:32:10]

On 2014/06/10 12:45:27, Søren Gjesse wrote:
> lgtm

Anders: would you open an issue to track this?

Once we change the build tools/VERSION to be 1.6, we can add a pre-release
version constraint without a problem

[kevmoo, 2014-07-07 19:38:48]

On 2014/06/10 18:32:10, kevmoo wrote:
> On 2014/06/10 12:45:27, Søren Gjesse wrote:
> > lgtm
> 
> Anders: would you open an issue to track this?
> 
> Once we change the build tools/VERSION to be 1.6, we can add a pre-release
> version constraint without a problem

We can run w/ this fix now, right? Just add the 1.6-dev (or whatever) version
constraint?

[nweiz, 2014-07-07 19:47:05]

On 2014/07/07 19:38:48, kevmoo wrote:
> On 2014/06/10 18:32:10, kevmoo wrote:
> > On 2014/06/10 12:45:27, Søren Gjesse wrote:
> > > lgtm
> > 
> > Anders: would you open an issue to track this?
> > 
> > Once we change the build tools/VERSION to be 1.6, we can add a pre-release
> > version constraint without a problem
> 
> We can run w/ this fix now, right? Just add the 1.6-dev (or whatever) version
> constraint?

I don't understand why this was reverted in the first place. It's always safe to
release a version with a narrow SDK constraint; pub simply won't select it on
older SDKs.