[EasyUnlock] Serialize and store BeaconSeeds along as cryptohome key metadata.

chrome/browser/chromeos/login/easy_unlock/easy_unlock_types.h

Index: chrome/browser/chromeos/login/easy_unlock/easy_unlock_types.h
diff --git a/chrome/browser/chromeos/login/easy_unlock/easy_unlock_types.h b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_types.h
index 3a3b8940f643b92529ba150d95271c363a71ec73..3657ad5f3c6afc59b9a7fff67c761caf91f494e1 100644
--- a/chrome/browser/chromeos/login/easy_unlock/easy_unlock_types.h
+++ b/chrome/browser/chromeos/login/easy_unlock/easy_unlock_types.h
@@ -7,6 +7,7 @@
 
 #include <string>
 #include <vector>
+#include "base/values.h"
 
 namespace chromeos {
 
@@ -16,6 +17,7 @@ extern const char kEasyUnlockKeyMetaNamePsk[];
 extern const char kEasyUnlockKeyMetaNamePubKey[];
 extern const char kEasyUnlockKeyMetaNameChallenge[];
 extern const char kEasyUnlockKeyMetaNameWrappedSecret[];
+extern const char kEasyUnlockKeyMetaNameSerializedBeaconSeeds[];
 
 // Device data that is stored with cryptohome keys.
 struct EasyUnlockDeviceKeyData {
@@ -38,6 +40,8 @@ struct EasyUnlockDeviceKeyData {
   std::string challenge;
   // Wrapped secret to mount cryptohome home.
   std::string wrapped_secret;
+  // Serialized BeaconSeeds used to identify this device.
+  std::string serialized_beacon_seeds;
 };
 typedef std::vector<EasyUnlockDeviceKeyData> EasyUnlockDeviceKeyDataList;