Revert of Decoupling rtc_base from Obj-C code (patchset #8 id:140001 of https://codereview.webrtc.org/3001623003/ )

Reason for revert:
It breaks a downstream project.

Original issue's description:
> Decoupling rtc_base from Obj-C code
>
> The goal of this CL is to separate Obj-C/Obj-C++ code from targets which have
> also C++ code (see https://bugs.chromium.org/p/webrtc/issues/detail?id=7743
> for more information).
>
> To achieve this we have created 2 targets (rtc_base_objc and rtc_base_generic)
> and rtc_base will act as a proxy between these targets (this way we can avoid a
> circular dependency between rtc_base_generic and rtc_base_objc).
>
> BUG=webrtc:7743
>
> Review-Url: https://codereview.webrtc.org/3001623003
> Cr-Commit-Position: refs/heads/master@{#19661}
> Committed: https://chromium.googlesource.com/external/webrtc/+/a0a5b98937de0f0bf90e17011d2cbc8c632cb409

TBR=kjellander@webrtc.org,kwiberg@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:7743

Review-Url: https://codereview.webrtc.org/3008103002
Cr-Original-Commit-Position: refs/heads/master@{#19664}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 791a8f611da8cc6b0668ccc03bf7525e6ba72a46
1 file changed