Move Field Trial Utils from chrome/common/variations to components/variations/field_trial_util

components/variations/DEPS

Index: components/variations/DEPS
diff --git a/components/variations/DEPS b/components/variations/DEPS
index 720e034fc7f9dd882705c12d087f54c090b7402b..11dfc78d95f34649daeaafed9df8ad159663df39 100644
--- a/components/variations/DEPS
+++ b/components/variations/DEPS
@@ -8,6 +8,7 @@ include_rules = [
   "+components/variations",
   "+crypto",
   "-net",
+  "+net/base",

[Alexei Svitkine (slow), 2016/10/31 17:22:38]

Why do we need this? I guess for the URL escaping?

I'd rather we don't depend on net/ since the metrics target is used by other
things - such as the ChromeOS daemon and having extra dependencies would bloat
that.

Can the escaping be moving to its own component?

[robliao, 2016/10/31 17:26:25]

Yes, this is specifically for URL escaping. We could use a separate component
for this, but I couldn't come up with an appropriate name and
components/variations seemed like an appropriate home.

Got a name? components/fieldtrial_utils or something?

[Alexei Svitkine (slow), 2016/10/31 17:29:18]

I was actually thinking the escaping from net/ could be it's own component. e.g.
components/url_escape

Alternatively, this can be a sub-directory inside components/metrics - like we
have service/ already which does depend on net. 

For example, components/metrics/field_trial_configs/

[robliao, 2016/10/31 17:35:12]

components/metrics/field_trial_configs sgtm.

Re: Refactoring URL Escaping
That will certainly be a more invasive change. (On the order of 40+ sites need
to be updated). 

+net/base seems to be the way to specifically depend on things in net/base
https://cs.chromium.org/search/?q=%5C%2Bnet/base+file:components&sq=package:c...

I suspect all of those components just rely on dead code elimination to remove
the unused parts of net from their components. What do you think?

[robliao, 2016/11/02 00:00:28]

Done.

   "+third_party/mt19937ar",
   "+third_party/protobuf",
   "+third_party/zlib/google",