If easy sign-in is set up, allow TPMTokenLoader to start before login

chromeos/tpm/tpm_token_loader.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_TPM_TPM_TOKEN_LOADER_H_
 #define CHROMEOS_TPM_TPM_TOKEN_LOADER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 48 matching lines @@
   // Returns true if the global instance has been initialized.
   static bool IsInitialized();
 
   // |crypto_task_runner| is the task runner that any synchronous crypto calls
   // should be made from, e.g. in Chrome this is the IO thread. Must be called
   // after the thread is started. When called, this will attempt to start TPM
   // token loading.
   void SetCryptoTaskRunner(
       const scoped_refptr<base::SequencedTaskRunner>& crypto_task_runner);
 
+  // Starts loading TPM system token, if not yet started. It should be called
+  // if the system token has to be loaded before a user logs in. By default (if
+  // |EnsureStarted| is not called) system token loading will start when the
+  // login state changes to LOGGED_IN_ACTIVE.
+  void EnsureStarted();
+
   // Checks if the TPM token is enabled. If the state is unknown, |callback|
   // will be called back once the TPM state is known.
   TPMTokenStatus IsTPMTokenEnabled(const TPMReadyCallback& callback);
 
   std::string tpm_user_pin() const { return tpm_user_pin_; }
 
  private:
   explicit TPMTokenLoader(bool for_test);
   ~TPMTokenLoader() override;
 
@@ skipping 30 matching lines @@
     TPM_TOKEN_INITIALIZED,
   };
   TPMTokenState tpm_token_state_;
 
   scoped_ptr<TPMTokenInfoGetter> tpm_token_info_getter_;
 
   // Cached TPM token info.
   int tpm_token_slot_id_;
   std::string tpm_user_pin_;
 
+  // Whether TPM system token loading may be started before user log in.
+  // This will be true iff |EnsureStarted| was called.
+  bool can_start_before_login_;
+
   base::ThreadChecker thread_checker_;
 
   // TaskRunner for crypto calls.
   scoped_refptr<base::SequencedTaskRunner> crypto_task_runner_;
 
   base::WeakPtrFactory<TPMTokenLoader> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TPMTokenLoader);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_TPM_TPM_TOKEN_LOADER_H_