Use GN buildflags and features to configure account consistency

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 66afbce583f362b0e1934723af0ff958bba89b91..a30c280baef596bb3a343efc7b8d633cc603db96 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -10,6 +10,7 @@ import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
 import("//components/offline_pages/features/features.gni")
 import("//components/os_crypt/features.gni")
+import("//components/signin/features.gni")
 import("//components/spellcheck/spellcheck_build_features.gni")
 import("//device/vr/features/features.gni")
 import("//extensions/features/features.gni")
@@ -1238,8 +1239,6 @@ split_static_library("browser") {
     "signin/chrome_signin_client_factory.h",
     "signin/chrome_signin_helper.cc",
     "signin/chrome_signin_helper.h",
-    "signin/dice_response_handler.cc",
-    "signin/dice_response_handler.h",
     "signin/gaia_cookie_manager_service_factory.cc",
     "signin/gaia_cookie_manager_service_factory.h",
     "signin/investigator_dependency_provider.cc",
@@ -1575,6 +1574,8 @@ split_static_library("browser") {
     "//components/security_state/core",
     "//components/sessions",
     "//components/signin/core/browser",
+    "//components/signin/core/common",
+    "//components/signin/core/common:signin_features",
     "//components/spellcheck:build_features",
     "//components/ssl_config",
     "//components/ssl_errors",
@@ -2004,6 +2005,12 @@ split_static_library("browser") {
       sources -= [ "background/background_mode_manager_aura.cc" ]
     }
   }
+  if (enable_dice_support) {
+    sources += [
+      "signin/dice_response_handler.cc",
+      "signin/dice_response_handler.h",
+    ]
+  }
   if (enable_spellcheck) {
     sources += [
       "spellchecker/spell_check_host_impl.cc",