[CrOS Tether] ProximityAuth WebUI improvement: show the local device's ID.

chrome/browser/signin/chrome_proximity_auth_client.cc

Index: chrome/browser/signin/chrome_proximity_auth_client.cc
diff --git a/chrome/browser/signin/chrome_proximity_auth_client.cc b/chrome/browser/signin/chrome_proximity_auth_client.cc
index da812d164b4a4f13e90f1fe389f17435d71275fc..ceba6a5f01239915ee49b79c1bf77e007abaaec5 100644
--- a/chrome/browser/signin/chrome_proximity_auth_client.cc
+++ b/chrome/browser/signin/chrome_proximity_auth_client.cc
@@ -21,6 +21,7 @@
 #include "components/cryptauth/cryptauth_client_impl.h"
 #include "components/cryptauth/cryptauth_device_manager.h"
 #include "components/cryptauth/cryptauth_enrollment_manager.h"
+#include "components/cryptauth/local_device_data_provider.h"
 #include "components/cryptauth/secure_message_delegate.h"
 #include "components/prefs/pref_service.h"
 #include "components/proximity_auth/logging/logging.h"
@@ -134,3 +135,10 @@ cryptauth::CryptAuthService* ChromeProximityAuthClient::GetCryptAuthService() {
   return ChromeCryptAuthServiceFactory::GetInstance()->GetForBrowserContext(
       profile_);
 }
+
+std::string ChromeProximityAuthClient::GetLocalDevicePublicKey() {
+  cryptauth::LocalDeviceDataProvider provider(GetCryptAuthService());
+  std::string local_public_key;
+  provider.GetLocalDeviceData(&local_public_key, nullptr);
+  return local_public_key;
+}