Remove Crit::Scope lock by using atomic bool property

webrtc/sdk/BUILD.gn

 # Copyright 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../build/webrtc.gni")
 if (is_mac) {
@@ skipping 50 matching lines @@
       libs = [ "AVFoundation.framework" ]
     }
     if (!build_with_chromium) {
       sources += [
         "objc/Framework/Classes/RTCFileLogger.mm",
         "objc/Framework/Headers/WebRTC/RTCFileLogger.h",
       ]
     }
   }
 
-  config("rtc_sdk_peerconnection_objc_warnings_config") {
-    if (is_clang) {
-      # TODO(tkchin): Make rtc_sdk_peerconnection_objc compile with the standard
-      # set of warnings.
-      # See https://bugs.chromium.org/p/webrtc/issues/detail?id=6308
-      cflags = [ "-Wno-thread-safety-analysis" ]
-    }
-  }
-
   rtc_static_library("rtc_sdk_peerconnection_objc") {
     sources = [
       "objc/Framework/Classes/RTCAVFoundationVideoSource+Private.h",
       "objc/Framework/Classes/RTCAVFoundationVideoSource.mm",
       "objc/Framework/Classes/RTCAudioSource+Private.h",
       "objc/Framework/Classes/RTCAudioSource.mm",
       "objc/Framework/Classes/RTCAudioTrack+Private.h",
       "objc/Framework/Classes/RTCAudioTrack.mm",
       "objc/Framework/Classes/RTCConfiguration+Private.h",
       "objc/Framework/Classes/RTCConfiguration.mm",
@@ skipping 97 matching lines @@
         "objc/Framework/Classes/RTCNSGLVideoView.m",
         "objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h",
       ]
       libs = [
         "CoreMedia.framework",
         "OpenGL.framework",
       ]
     }
 
     configs += [
-      ":rtc_sdk_peerconnection_objc_warnings_config",
       "..:common_objc",
       "//build/config/compiler:enable_arc",
     ]
 
     public_configs = [ ":rtc_sdk_common_objc_config" ]
 
     if (is_clang) {
       # Suppress warnings from the Chromium Clang plugins.
       # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
@@ skipping 125 matching lines @@
       public_configs = [ ":rtc_sdk_common_objc_config" ]
 
       if (is_clang) {
         # Suppress warnings from the Chromium Clang plugins.
         # See http://code.google.com/p/webrtc/issues/detail?id=163 for details.
         configs -= [ "//build/config/clang:find_bad_constructs" ]
       }
     }
   }
 }