Roll WebRTC 17520:17539 (17 commits)

Changes: https://chromium.googlesource.com/external/webrtc/trunk/webrtc.git/+log/ace8d26..4136d39

$ git log ace8d26..4136d39 --date=short --no-merges --format=%ad %ae %s
2017-04-05 nisse@webrtc.org Replace use of system_wrappers/include/logging.h by base/logging.h.
2017-04-05 magjed@webrtc.org Android: Remove VideoCapturerAndroid
2017-04-05 ilnik@webrtc.org Reland of Move video_encoder.h and video_decoder.h to /api and create GN targets for them (patchset chromium#1 id:1 of https://codereview.webrtc.org/2794033002/ )
2017-04-05 nisse@webrtc.org Move SelectMediaType from RampUpTester to BaseTest.
2017-04-04 asapersson@webrtc.org Add histogram stats for number of cpu/quality adapt changes per minute for sent video streams:
2017-04-04 zstein@webrtc.org Add a minimal RtpTransport class for use by BaseChannel.
2017-04-04 jtteh@webrtc.org [iOS] Changed ptr to const ref for RTCConfiguration initialization
2017-04-04 yujo@chromium.org Trivial data() and mutable_data() implementations
2017-04-04 alessiob@webrtc.org README.md with deps, build, usage, troubleshooting
2017-04-04 guidou@webrtc.org Revert of Deliver video frames on Android, on the decode thread. (patchset chromium#7 id:120001 of https://codereview.webrtc.org/2764573002/ )
2017-04-04 alessiob@webrtc.org Javascript audio player for the exported HTML file.
2017-04-04 asapersson@webrtc.org Add number of quality adapt changes to VideoSendStream stats.
2017-04-04 tommi@webrtc.org Deliver video frames on Android, on the decode thread.
2017-04-04 alessiob@webrtc.org Evaluation scores export library and CSS file for the exported HTML file
2017-04-04 alessiob@webrtc.org Reland of Export library that generates an HTLM file with the scores organized in tables. (patchset chromium#1 id:1 of https://codereview.webrtc.org/2791293002/ )
2017-04-04 danilchap@webrtc.org Simplify RTPSender::RegisterRtpHeaderExtension DCHECK instead of run-time check extension type is correct.
2017-04-04 kthelgason@webrtc.org Make sure we observe enough frames before scaling.

TBR=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_archive_rel_ng;master.tryserver.chromium.mac:mac_chromium_archive_rel_ng
BUG=

Review-Url: https://codereview.chromium.org/2798023002
Cr-Commit-Position: refs/heads/master@{#462351}

DEPS

@@ -232,7 +232,7 @@ deps = {
     Var('chromium_git') + '/native_client/src/third_party/scons-2.0.1.git' + '@' + '1c1550e17fc26355d08627fbdec13d8291227067',
 
   'src/third_party/webrtc':
-    Var('chromium_git') + '/external/webrtc/trunk/webrtc.git' + '@' + 'ace8d2683e322f3ebc76fe138c533112764c2636', # commit position 17520
+    Var('chromium_git') + '/external/webrtc/trunk/webrtc.git' + '@' + '4136d392b42aa44168270416bdba506126a9ab24', # commit position 17539
 
   'src/third_party/openmax_dl':
     Var('chromium_git') + '/external/webrtc/deps/third_party/openmax.git' + '@' +  Var('openmax_dl_revision'),