Enable webview-based sign-in to chrome.

components/signin/core/common/profile_management_switches.cc

Index: components/signin/core/common/profile_management_switches.cc
diff --git a/components/signin/core/common/profile_management_switches.cc b/components/signin/core/common/profile_management_switches.cc
index 6d7b089eacc2b66d2c3d8553ce60ddeca5792aa0..90b1effc44548dd275adf6326c8632c32b5fa76f 100644
--- a/components/signin/core/common/profile_management_switches.cc
+++ b/components/signin/core/common/profile_management_switches.cc
@@ -135,8 +135,13 @@ bool IsEnableWebBasedSignin() {
 }
 
 bool IsEnableWebviewBasedSignin() {
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kEnableWebviewBasedSignin);
+  // For now, the webview is enabled only for desktop.
+#if defined(OS_CHROMEOS)
+  return false;
+#else
+  return !base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableIframeBasedSignin);
+#endif
 }
 
 bool IsExtensionsMultiAccount() {