Remove webrtc/libjingle/{examples,session}.

Remove webrtc/libjingle/{examples,session}.

webrtc/libjingle/ is deprecated and these targets (unlike xmllite/xmpp)
are not currently in use in Chromium (which blocks removing the whole
webrtc/libjingle/ folder).

BUG=
R=juberti@webrtc.org

Committed: https://chromium.googlesource.com/external/webrtc/+/f5642913c9b11e1b3b24ba20b5c696dd48b9d37f

[pbos-webrtc, 2015-06-11 09:22:07]

PTAL, pthatcher@ asked me to create this CL, so you can probably sync on your
side. :)

Used includes in webrtc/libjingle/ in Chromium are (xmllite and xmpp):

pbos@deimos:~/chromium/src (master)$ git grep -h third_party/webrtc/libjingle |
sed -e 's/[0-9]\+://' | grep include | sort | uniq
#include "third_party/webrtc/libjingle/xmllite/qname.h"
#include "third_party/webrtc/libjingle/xmllite/xmlbuilder.h"
#include "third_party/webrtc/libjingle/xmllite/xmlconstants.h"
#include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
#include "third_party/webrtc/libjingle/xmllite/xmlparser.h"
#include "third_party/webrtc/libjingle/xmllite/xmlprinter.h"
#include "third_party/webrtc/libjingle/xmpp/asyncsocket.h"
#include "third_party/webrtc/libjingle/xmpp/constants.h"

[juberti1, 2015-06-11 18:18:28]

On 2015/06/11 at 09:22:07, pbos wrote:
> PTAL, pthatcher@ asked me to create this CL, so you can probably sync on your
side. :)
> 
> Used includes in webrtc/libjingle/ in Chromium are (xmllite and xmpp):
> 
> pbos@deimos:~/chromium/src (master)$ git grep -h third_party/webrtc/libjingle
| sed -e 's/[0-9]\+://' | grep include | sort | uniq
> #include "third_party/webrtc/libjingle/xmllite/qname.h"
> #include "third_party/webrtc/libjingle/xmllite/xmlbuilder.h"
> #include "third_party/webrtc/libjingle/xmllite/xmlconstants.h"
> #include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
> #include "third_party/webrtc/libjingle/xmllite/xmlparser.h"
> #include "third_party/webrtc/libjingle/xmllite/xmlprinter.h"
> #include "third_party/webrtc/libjingle/xmpp/asyncsocket.h"
> #include "third_party/webrtc/libjingle/xmpp/constants.h"

lgtm

[pbos-webrtc, 2015-06-12 11:13:58]

Committed patchset #1 (id:1) manually as
f5642913c9b11e1b3b24ba20b5c696dd48b9d37f (presubmit successful).