Remove dcheck for unkonwn signin source

chrome/browser/ui/sync/one_click_signin_helper.cc

Index: chrome/browser/ui/sync/one_click_signin_helper.cc
diff --git a/chrome/browser/ui/sync/one_click_signin_helper.cc b/chrome/browser/ui/sync/one_click_signin_helper.cc
index fceb3e6035a798f03f14e8afc46a01771eb6f361..19948526e27236d8cb34f18d2300fbc132415a92 100644
--- a/chrome/browser/ui/sync/one_click_signin_helper.cc
+++ b/chrome/browser/ui/sync/one_click_signin_helper.cc
@@ -754,8 +754,8 @@ void OneClickSigninHelper::LogHistogramValue(
       // This switch statement needs to be updated when the enum Source changes.
       COMPILE_ASSERT(signin::SOURCE_UNKNOWN == 12,
                      kSourceEnumHasChangedButNotThisSwitchStatement);
-      NOTREACHED();
-      return;
+      UMA_HISTOGRAM_ENUMERATION("Signin.UnknownActions", action,
+                                one_click_signin::HISTOGRAM_MAX);
   }
   UMA_HISTOGRAM_ENUMERATION("Signin.AllAccessPointActions", action,
                             one_click_signin::HISTOGRAM_MAX);