cryptohome: Add dbus method and signal name for encryption migration.

chromeos/dbus/cryptohome_client.h

Index: chromeos/dbus/cryptohome_client.h
diff --git a/chromeos/dbus/cryptohome_client.h b/chromeos/dbus/cryptohome_client.h
index 8fc61f94b0e4f64241a565479d13f9aad0ed5e41..af86fc1248de9a146bb1a5173f6db0f43769ced6 100644
--- a/chromeos/dbus/cryptohome_client.h
+++ b/chromeos/dbus/cryptohome_client.h
@@ -91,6 +91,10 @@ class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
            bool result,
            const cryptohome::BaseReply& reply)> ProtobufMethodCallback;
 
+  // A callback to handle DircryptoMigrationProgress signals.
+  typedef base::Callback<void(uint64_t current, uint64_t total)>
+      DircryptoMigrationProgessHandler;
+
   ~CryptohomeClient() override;
 
   // Factory function, creates a new instance and returns ownership.
@@ -116,6 +120,11 @@ class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
   // partition is running out of disk space.
   virtual void SetLowDiskSpaceHandler(const LowDiskSpaceHandler& handler) = 0;
 
+  // A callback to handle DircryptoMigrationProgress signals.  |handler| is
+  // called periodicaly during a migration is performed by cryptohomed.

[Daniel Erat, 2017/03/14 15:37:36]

nit: "called periodically while a migration is being performed by cryptohomed."

is it guaranteed to be called once after the migration is done? is there some
other way for chrome to know when it's done?

[kinaba, 2017/03/15 08:17:30]

My intent is that the callback from MigrateToDircrypto fires
only after the migration is finished (by success or failure.)
Adding a comment below as you suggested.

+  virtual void SetDircryptoMigrationProgressHandler(
+      const DircryptoMigrationProgessHandler& handler) = 0;
+
   // Runs the callback as soon as the service becomes available.
   virtual void WaitForServiceToBeAvailable(
       const WaitForServiceToBeAvailableCallback& callback) = 0;
@@ -555,6 +564,15 @@ class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
       const cryptohome::FlushAndSignBootAttributesRequest& request,
       const ProtobufMethodCallback& callback) = 0;
 
+  // Asynchronously calls MigrateToDicrypto method. |callback| is called after
+  // method call, and with reply protobuf.

[Daniel Erat, 2017/03/14 15:37:36]

does the callback get invoked immediately, or only after the migration has
finished? it'd be good to mention that here.

[kinaba, 2017/03/15 08:17:30]

Done.

+  // MigrateToDicrypto attempts to migrate the home dir using given

[Daniel Erat, 2017/03/14 15:37:37]

nit: MigrateToDirCrypto

[kinaba, 2017/03/15 08:17:30]

Done.

+  // authorization, to the new "dicrypto" encryption.

[Daniel Erat, 2017/03/14 15:37:36]

nit: "dircrypto", also remove comma on this line

[kinaba, 2017/03/15 08:17:30]

Done.

+  virtual void MigrateToDircrypto(
+      const cryptohome::Identification& cryptohome_id,
+      const cryptohome::AuthorizationRequest& auth,
+      const ProtobufMethodCallback& callback) = 0;
+
  protected:
   // Create() should be used instead.
   CryptohomeClient();