Reason for revert:
Breaks iOS framework builder.
Original issue's description:
> Enable -Wunused-lambda-capture warning
>
> This should prevent some build errors downstream.
> The warning is currrently disabled in Chromium:
> https://cs.chromium.org/chromium/src/build/config/compiler/BUILD.gn?rcl=735aa36217a394455f70aad87e2c844053fd810a&l=1214
> (see https://crbug.com/681136 for more info).
>
> BUG=webrtc:7133
> NOTRY=True
>
> Review-Url: https://codereview.webrtc.org/2999403002
> Cr-Commit-Position: refs/heads/master@{#19466}
> Committed: fd7cffa433
TBR=charujain@webrtc.org,charujain@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7133
Review-Url: https://codereview.webrtc.org/3007483002
Cr-Commit-Position: refs/heads/master@{#19473}
Name: WebRTC URL: http://www.webrtc.org Version: 90 License: BSD License File: LICENSE Description: WebRTC provides real time voice and video processing functionality to enable the implementation of PeerConnection/MediaStream. Third party code used in this project is described in the file LICENSE_THIRD_PARTY.