Add media constraint-key constants for generating offers and answers

Add media constraint-key constants for generating offers and answers

Similar to the existing constants for the media constraint-keys intended
for media sources, add the constants for the standard keys to generate
offers and answers.

This patch also adds a few comments to RTCMediaConstraints.h, to give
a better clue on the intended usage scope of declared media-constraint
keys and values.

BUG=webrtc:7722
Review-Url: https://codereview.webrtc.org/2908013002
Cr-Commit-Position: refs/heads/master@{#18362}
Committed: https://chromium.googlesource.com/external/webrtc/+/7b3eca9940e4e9407df2024248a212063680b6d6

[VladimirTechMan, 2017-05-28 22:26:58]

Description was changed from

==========
Add media constraint-key constants for generating offers and answers

Similar to the existing constants for the media constraint-keys intended
for media sources, add the constants for the standard keys to generate
offers and answers.

This patch also adds a few comments to RTCMediaConstraints.h, to give
a better clue on the intended usage scope of declared media-constraint
keys and values.

BUG=None
==========

to

==========
Add media constraint-key constants for generating offers and answers

Similar to the existing constants for the media constraint-keys intended
for media sources, add the constants for the standard keys to generate
offers and answers.

This patch also adds a few comments to RTCMediaConstraints.h, to give
a better clue on the intended usage scope of declared media-constraint
keys and values.

BUG=webrtc:7722
==========

[VladimirTechMan, 2017-05-28 22:26:59]

vladimirtechman@gmail.com changed reviewers:
+ kjellander@webrtc.org, magjed@webrtc.org

[magjed_webrtc, 2017-05-29 13:02:28]

lgtm

[VladimirTechMan, 2017-05-30 17:12:03]

On 2017/05/29 13:02:28, magjed_webrtc wrote:
> lgtm

The patch updated to match the updated structure of folders containing Obj-C SDK
classes.

[VladimirTechMan, 2017-06-01 01:04:37]

The CQ bit was checked by vladimirtechman@gmail.com

[VladimirTechMan, 2017-06-01 01:04:38]

The patchset sent to the CQ was uploaded after l-g-t-m from magjed@webrtc.org
Link to the patchset: https://codereview.webrtc.org/2908013002/#ps20001 (title:
"Add media constraint-key constants for generating offers and answers")

[commit-bot: I haz the power, 2017-06-01 01:04:41]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-06-01 01:25:49]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1496279077723830,
"parent_rev": "dacac34cfbda68d939e0fe7b34ad0c27cc1efa77", "commit_rev":
"7b3eca9940e4e9407df2024248a212063680b6d6"}

[commit-bot: I haz the power, 2017-06-01 01:25:54]

Description was changed from

==========
Add media constraint-key constants for generating offers and answers

Similar to the existing constants for the media constraint-keys intended
for media sources, add the constants for the standard keys to generate
offers and answers.

This patch also adds a few comments to RTCMediaConstraints.h, to give
a better clue on the intended usage scope of declared media-constraint
keys and values.

BUG=webrtc:7722
==========

to

==========
Add media constraint-key constants for generating offers and answers

Similar to the existing constants for the media constraint-keys intended
for media sources, add the constants for the standard keys to generate
offers and answers.

This patch also adds a few comments to RTCMediaConstraints.h, to give
a better clue on the intended usage scope of declared media-constraint
keys and values.

BUG=webrtc:7722

Review-Url: https://codereview.webrtc.org/2908013002
Cr-Commit-Position: refs/heads/master@{#18362}
Committed:
https://chromium.googlesource.com/external/webrtc/+/7b3eca9940e4e9407df202424...
==========

[commit-bot: I haz the power, 2017-06-01 01:25:55]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/external/webrtc/+/7b3eca9940e4e9407df202424...