[CrOS Tether]: Add LocalDeviceDataProvider, which fetches device data for the local device.

chromeos/components/tether/local_device_data_provider.h

Index: chromeos/components/tether/local_device_data_provider.h
diff --git a/chromeos/components/tether/local_device_data_provider.h b/chromeos/components/tether/local_device_data_provider.h
new file mode 100644
index 0000000000000000000000000000000000000000..240cc6e6c7b7509c2b0d842212e90bb4a257b165
--- /dev/null
+++ b/chromeos/components/tether/local_device_data_provider.h
@@ -0,0 +1,88 @@
+// Copyright 2016 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_COMPONENTS_TETHER_LOCAL_DEVICE_DATA_PROVIDER_H
+#define CHROMEOS_COMPONENTS_TETHER_LOCAL_DEVICE_DATA_PROVIDER_H
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+
+namespace cryptauth {
+class BeaconSeed;
+class ExternalDeviceInfo;
+class CryptAuthDeviceManager;
+class CryptAuthEnrollmentManager;
+}
+
+namespace chromeos {
+
+namespace tether {
+
+// Fetches CryptAuth data about the local device (i.e., the device on which this
+// code is running) for the current user (i.e., the one which is logged-in).
+class LocalDeviceDataProvider {
+ public:
+  LocalDeviceDataProvider(
+      const cryptauth::CryptAuthDeviceManager* cryptauth_device_manager,
+      const cryptauth::CryptAuthEnrollmentManager*
+          cryptauth_enrollment_manager);
+  virtual ~LocalDeviceDataProvider();
+
+  // Fetches the public key and/or the beacon seeds for the local device.
+  // Returns whether the operation succeeded. If |nullptr| is passed as a
+  // parameter, the associated data will not be fetched.
+  bool GetLocalDeviceData(
+      std::string* public_key_out,
+      std::vector<cryptauth::BeaconSeed>* beacon_seeds_out) const;
+
+ private:
+  friend class LocalDeviceDataProviderTest;
+
+  class LocalDeviceDataProviderContext {

[Ryan Hansberry, 2016/12/19 20:25:31]

In your HostScanScheduler CL, tengs@ preferred the name Delegate over Context
for a similar inner class. Does that same notion apply here?

[Kyle Horimoto, 2016/12/19 21:23:54]

Done.

+   public:
+    virtual ~LocalDeviceDataProviderContext() {}
+    virtual std::string GetUserPublicKey() const = 0;
+    virtual std::vector<cryptauth::ExternalDeviceInfo> GetSyncedDevices()
+        const = 0;
+  };
+
+  class LocalDeviceDataProviderContextImpl
+      : public LocalDeviceDataProviderContext {
+   public:
+    LocalDeviceDataProviderContextImpl(
+        const cryptauth::CryptAuthDeviceManager* cryptauth_device_manager,
+        const cryptauth::CryptAuthEnrollmentManager*
+            cryptauth_enrollment_manager);
+    ~LocalDeviceDataProviderContextImpl() override;
+
+    std::string GetUserPublicKey() const override;
+    std::vector<cryptauth::ExternalDeviceInfo> GetSyncedDevices()
+        const override;
+
+   private:
+    // Not owned and must outlive this instance.
+    const cryptauth::CryptAuthDeviceManager* const cryptauth_device_manager_;
+
+    // Not owned and must outlive this instance.
+    const cryptauth::CryptAuthEnrollmentManager* const
+        cryptauth_enrollment_manager_;
+  };
+
+  LocalDeviceDataProvider(
+      std::unique_ptr<LocalDeviceDataProviderContext> context);
+
+  std::unique_ptr<LocalDeviceDataProviderContext> context_;
+
+  DISALLOW_COPY_AND_ASSIGN(LocalDeviceDataProvider);
+};
+
+}  // namespace tether
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_TETHER_LOCAL_DEVICE_DATA_PROVIDER_H