Use Finch flag instead of command line for Expect CT reporting

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 741093599fc0c2aa9fc8bd2c3ea0cfb1a5e094e9..9b18acafb528fe4f888c2b7374171913e58256f3 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -400,10 +400,6 @@ const char kEnableDeviceDiscoveryNotifications[] =
 // Enables Domain Reliability Monitoring.
 const char kEnableDomainReliability[] = "enable-domain-reliability";
 
-// Enables Expect CT reporting, which sends reports for opted-in sites
-// that don't serve sufficient Certificate Transparency information.
-const char kEnableExpectCTReporting[] = "enable-expect-ct-reporting";
-
 // Enables experimental hotword features specific to always-on.
 const char kEnableExperimentalHotwordHardware[] = "enable-hotword-hardware";