Media Galleries API: Use Scheduler in MediaGalleriesPreferences initialization.

Media Galleries API: Use Scheduler in MediaGalleriesPreferences initialization.

Ignore the Scheduler code included. Just see deltas on MediaGalleriesPreferences.

BUG=151701

[tommycli, 2013-09-19 22:25:20]

gbillock: This is a delta on the MediaGalleriesPreferences race fix that uses
your scheduler. It doesn't seem to really reduce SLOC, but it does make it
easier to read imo.

[Greg Billock, 2013-09-19 22:34:07]

https://codereview.chromium.org/24298002/diff/15001/chrome/browser/media_gall...
File chrome/browser/media_galleries/media_galleries_preferences.cc (right):

https://codereview.chromium.org/24298002/diff/15001/chrome/browser/media_gall...
chrome/browser/media_galleries/media_galleries_preferences.cc:387:
b.Build()->Start();
This looks nice. Agreed it makes it easier to follow.

It'd benefit from a helper method like

RunAsync(const base::Callback<base::Closure>), which would enable you to not
need any ContinueClosure call.

https://codereview.chromium.org/24298002/diff/15001/chrome/browser/media_gall...
chrome/browser/media_galleries/media_galleries_preferences.cc:516: if
(!callback.is_null())
Although we may not use it, this is a nice testability enhancement -- you can
instrument the method out to this callback instead of having to subclass, use a
mock, or something.

[tommycli, 2013-09-19 22:37:05]

https://codereview.chromium.org/24298002/diff/15001/chrome/browser/media_gall...
File chrome/browser/media_galleries/media_galleries_preferences.cc (right):

https://codereview.chromium.org/24298002/diff/15001/chrome/browser/media_gall...
chrome/browser/media_galleries/media_galleries_preferences.cc:387:
b.Build()->Start();
On 2013/09/19 22:34:08, Greg Billock wrote:
> This looks nice. Agreed it makes it easier to follow.
> 
> It'd benefit from a helper method like
> 
> RunAsync(const base::Callback<base::Closure>), which would enable you to not
> need any ContinueClosure call.

Yeah! That'd be pimp. I'm also a bit annoyed that i have to write
RunAsync(base::Bind( everywhere. It's probably a huge difficulty to remove the
"base::Bind(" string due to the variable number of arguments huh?

https://codereview.chromium.org/24298002/diff/15001/chrome/browser/media_gall...
chrome/browser/media_galleries/media_galleries_preferences.cc:516: if
(!callback.is_null())
On 2013/09/19 22:34:08, Greg Billock wrote:
> Although we may not use it, this is a nice testability enhancement -- you can
> instrument the method out to this callback instead of having to subclass, use
a
> mock, or something.

Yeah I could see exploiting that in a test. Making sure it gets called for
instance.