Add flag to control whether cryptotoken calls are proxied to webauthn

Bug: 902554
Change-Id: Ic14cfeaa7b041c316bcb77066d69a7b701bd5a62
Reviewed-on: https://chromium-review.googlesource.com/c/1321260
Commit-Queue: Kim Paulhamus <kpaulhamus@chromium.org>
Reviewed-by: Jun Choi <hongjunchoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607001}

device/fido/features.cc

@@ -16,4 +16,7 @@ const base::Feature kWebAuthUseNativeWinApi{"WebAuthenticationUseNativeWinApi",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // defined(OS_WIN)
 
+extern const base::Feature kWebAuthProxyCryptotoken{
+    "WebAuthenticationProxyCryptotoken", base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace device

device/fido/features.h

@@ -16,6 +16,10 @@ COMPONENT_EXPORT(DEVICE_FIDO)
 extern const base::Feature kWebAuthUseNativeWinApi;
 #endif  // defined(OS_WIN)
 
+// Controls the proxying of Cryptotoken requests through WebAuthn.
+COMPONENT_EXPORT(DEVICE_FIDO)
+extern const base::Feature kWebAuthProxyCryptotoken;
+
 }  // namespace device
 
 #endif  // DEVICE_FIDO_FEATURES_H_