Fill is_chrome_signin_password field in the password entry pings.

components/password_manager/core/browser/password_reuse_detector_consumer.h

Index: components/password_manager/core/browser/password_reuse_detector_consumer.h
diff --git a/components/password_manager/core/browser/password_reuse_detector_consumer.h b/components/password_manager/core/browser/password_reuse_detector_consumer.h
index b621b777e4fa024255dded6d761721c11b1a6d6c..fb6dc8c817aea22cf472e3199515816c8beac662 100644
--- a/components/password_manager/core/browser/password_reuse_detector_consumer.h
+++ b/components/password_manager/core/browser/password_reuse_detector_consumer.h
@@ -21,8 +21,8 @@ class PasswordReuseDetectorConsumer
   virtual ~PasswordReuseDetectorConsumer();
 
   // Called when a password reuse is found.
-  // |legitimate_domain| is the domain on which |password| is saved or the sync
-  // domain if |password| is a sync password.
+  // |legitimate_domain| is the domain on which |password| is saved or
+  // safe_browsing::kChromeSyncDomain if |password| is a sync password.

[dvadym, 2017/06/02 09:28:55]

Would it be possible to move kChromeSyncDomain to PasswordManager code, for
example to this file? It looks like kChromeSyncDomain is part of PasswordReuse
API so it's more logical to have it inside Reuse detection code. So if we decide
to use Password Reuse detection in our code, it will be not needed to add
SafeBrowsing dependencies.

[Jialiu Lin, 2017/06/06 01:00:53]

Done.
I thought I would encounter some circular dependencies. It turns out
PasswordReuseDetectionManager no longer needs to depends on
PasswordProtectionService. Constant moved to password_manager namespace. 

[dvadym, 2017/06/06 09:10:19]

Great, thanks for moving it.

   // |saved_passwords| is total number of passwords stored in Password Manager.
   // |number_matches| is a number of sites on which |password| is saved.
   virtual void OnReuseFound(const base::string16& password,