Add third_party/webrtc_overrides.

Add third_party/webrtc_overrides.

This is the first step in moving the overrides files from WebRTC to Chromium. See bug comment #65 for all steps.

The files are just copied from the WebRTC repo https://chromium.googlesource.com/external/webrtc/trunk/webrtc.git/+/master/overrides/ with updated comments and licence headers.

In these files, it's only the implementation files that depend on Chromium, thus removing WebRTC's dependency on Chromium when the move is complete.

BUG=468375
Committed: https://crrev.com/5529b560102be7c820ca8d54112cfc9896a3312f
Cr-Commit-Position: refs/heads/master@{#351528}

[Henrik Grunell, 2015-09-18 12:37:31]

grunell@chromium.org changed reviewers:
+ cpu@chromium.org

[Henrik Grunell, 2015-09-22 06:38:33]

grunell@chromium.org changed reviewers:
+ jam@chromium.org
- cpu@chromium.org

[Henrik Grunell, 2015-09-22 06:40:26]

Switching reviewer since no review in two days.

John, ptal.

[jam, 2015-09-22 15:49:39]

https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
File third_party/webrtc_overrides/DEPS (right):

https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
third_party/webrtc_overrides/DEPS:4: '+third_party/webrtc',
is this a circular dependency? i.e. i think third_party/webrtc will also depend
on webrtc_overrides right?

[Henrik Grunell, 2015-09-22 18:57:22]

https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
File third_party/webrtc_overrides/DEPS (right):

https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
third_party/webrtc_overrides/DEPS:4: '+third_party/webrtc',
On 2015/09/22 15:49:38, jam wrote:
> is this a circular dependency? i.e. i think third_party/webrtc will also
depend
> on webrtc_overrides right?

Well, the overrides replaces the corresponding files in third_party/webrtc, so
it "depends" on the overrides in that sense. Otherwise it wouldn't be overrides,
right? Fwiw there's no DEPS file in third_party/webrtc and there's no explicit
including from webrtc_overrides in third_party/webrtc, only include order magic.

[jam, 2015-09-23 18:17:32]

On 2015/09/22 18:57:22, Henrik Grunell wrote:
>
https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
> File third_party/webrtc_overrides/DEPS (right):
> 
>
https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
> third_party/webrtc_overrides/DEPS:4: '+third_party/webrtc',
> On 2015/09/22 15:49:38, jam wrote:
> > is this a circular dependency? i.e. i think third_party/webrtc will also
> depend
> > on webrtc_overrides right?
> 
> Well, the overrides replaces the corresponding files in third_party/webrtc,

this seems fragile.

can we do this via dependency injection and interfaces?

> so
> it "depends" on the overrides in that sense. Otherwise it wouldn't be
overrides,
> right? Fwiw there's no DEPS file in third_party/webrtc and there's no explicit
> including from webrtc_overrides in third_party/webrtc, only include order
magic.

[Henrik Grunell, 2015-09-23 18:46:02]

On 2015/09/23 18:17:32, jam wrote:
> On 2015/09/22 18:57:22, Henrik Grunell wrote:
> >
>
https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
> > File third_party/webrtc_overrides/DEPS (right):
> > 
> >
>
https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
> > third_party/webrtc_overrides/DEPS:4: '+third_party/webrtc',
> > On 2015/09/22 15:49:38, jam wrote:
> > > is this a circular dependency? i.e. i think third_party/webrtc will also
> > depend
> > > on webrtc_overrides right?
> > 
> > Well, the overrides replaces the corresponding files in third_party/webrtc,
> 
> this seems fragile.
> 
> can we do this via dependency injection and interfaces?

Surely for the win socket init.

For logging it's more complicated, but possible. I'm not sure exactly how
complicated though. There will be drawbacks of course. For example we'll move
the log-is-on check further away from the logging place, since that has to be
checked in Chrome, and we'll have to pass log messages another step or two
before we can check if we even care about them. (I.e. verbosity level and
per-file enabling.)

How are other third party libs dealing with similar situations?

> 
> > so
> > it "depends" on the overrides in that sense. Otherwise it wouldn't be
> overrides,
> > right? Fwiw there's no DEPS file in third_party/webrtc and there's no
explicit
> > including from webrtc_overrides in third_party/webrtc, only include order
> magic.

[tommi (sloooow) - chröme, 2015-09-28 15:40:02]

tommi@chromium.org changed reviewers:
+ tommi@chromium.org

[tommi (sloooow) - chröme, 2015-09-28 15:40:03]

https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
File third_party/webrtc_overrides/DEPS (right):

https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
third_party/webrtc_overrides/DEPS:4: '+third_party/webrtc',
On 2015/09/22 15:49:38, jam wrote:
> is this a circular dependency? i.e. i think third_party/webrtc will also
depend
> on webrtc_overrides right?

Not really.  There's no explicit dependency from webrtc over to
webrtc_overrides.  The webrtc_overrides folder is just a regular overrides
folder where we inject Chromium implementations into third party libraries via
files (essentially a form of an interface if you will) that the library defines.

See e.g. this original file (literally a "random" example):
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/cachei...

overridden here for Chromium:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/cachei...

[jam, 2015-09-29 20:44:59]

On 2015/09/28 15:40:03, tommi wrote:
>
https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
> File third_party/webrtc_overrides/DEPS (right):
> 
>
https://codereview.chromium.org/1345873004/diff/20001/third_party/webrtc_over...
> third_party/webrtc_overrides/DEPS:4: '+third_party/webrtc',
> On 2015/09/22 15:49:38, jam wrote:
> > is this a circular dependency? i.e. i think third_party/webrtc will also
> depend
> > on webrtc_overrides right?
> 
> Not really.  There's no explicit dependency from webrtc over to
> webrtc_overrides.  The webrtc_overrides folder is just a regular overrides
> folder where we inject Chromium implementations into third party libraries via
> files (essentially a form of an interface if you will) that the library
defines.
> 
> See e.g. this original file (literally a "random" example):
>
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/cachei...
> 
> overridden here for Chromium:
>
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/cachei...

I see, thanks for the explanation. lgtm

[Henrik Grunell, 2015-09-30 09:14:34]

The CQ bit was checked by grunell@chromium.org

[commit-bot: I haz the power, 2015-09-30 09:14:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1345873004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1345873004/20001

[commit-bot: I haz the power, 2015-09-30 09:31:30]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-09-30 09:31:31]

Try jobs failed on following builders:
  linux_android_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_android_r...)

[Henrik Grunell, 2015-09-30 09:43:47]

The CQ bit was checked by grunell@chromium.org

[Henrik Grunell, 2015-09-30 09:43:47]

The patchset sent to the CQ was uploaded after l-g-t-m from jam@chromium.org
Link to the patchset: https://codereview.chromium.org/1345873004/#ps40001
(title: "Corrected licence file path.")

[commit-bot: I haz the power, 2015-09-30 09:44:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1345873004/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1345873004/40001

[commit-bot: I haz the power, 2015-09-30 09:55:27]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-09-30 09:56:41]

Patchset 3 (id:??) landed as
https://crrev.com/5529b560102be7c820ca8d54112cfc9896a3312f
Cr-Commit-Position: refs/heads/master@{#351528}