Start and stop RTC event logs from private extension API.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index cf343b94d0da41abee06445fd27670a1a922c8fd..bf57fb59afbdd37e44d75e57655c5677c5dec0f2 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -499,6 +499,10 @@ const char kEnableQuic[]                    = "enable-quic";
 // This only has an effect if QUIC protocol is enabled.
 const char kEnableQuicPortSelection[]       = "enable-quic-port-selection";
 
+// If the WebRTC logging private API is active, enables WebRTC event logging.
+const char kEnableWebRtcEventLoggingFromExtension[] =
+    "enable-webrtc-event-logging-from-extension";
+
 // Enables support for HTTP alternative services.
 const char kEnableAlternativeServices[] = "enable-alternative-services";