Add include_examples GYP variable.

Add include_examples GYP variable.

To make it possible to exclude the examples when running
GYP on all.gyp.
The webrtc_examples.gyp already has an OS=="android" condition
inside it, so there's no need to check that before including it.

BUG=webrtc:4242
Committed: https://crrev.com/31acf3d1208b294ba86cbcdfa475a5c94229ae3a
Cr-Commit-Position: refs/heads/master@{#9556}

[kjellander_webrtc, 2015-06-20 17:28:03]

kjellander@webrtc.org changed reviewers:
+ tommi@webrtc.org

[phoglund_chromium, 2015-07-08 13:10:13]

phoglund@chromium.org changed reviewers:
+ andrew@webrtc.org, phoglund@chromium.org
- tommi@webrtc.org

[phoglund_chromium, 2015-07-08 13:10:13]

Andrew, can you review this? We need it for the libjingle import.

[Andrew MacDonald, 2015-07-08 21:39:10]

lgtm

Sorry, missed this.

[phoglund, 2015-07-09 07:33:24]

On 2015/07/08 21:39:10, andrew wrote:
> lgtm
> 
> Sorry, missed this.

No worries at all, I swapped you in for tommi yesterday :) It looks like you
missed this one but that's not the case.

[phoglund, 2015-07-09 07:33:41]

The CQ bit was checked by phoglund@webrtc.org

[commit-bot: I haz the power, 2015-07-09 07:33:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1196623006/1

[commit-bot: I haz the power, 2015-07-09 08:19:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-09 08:19:06]

Patchset 1 (id:??) landed as
https://crrev.com/31acf3d1208b294ba86cbcdfa475a5c94229ae3a
Cr-Commit-Position: refs/heads/master@{#9556}