[CrOS MultiDevice] DeviceSync: Add GetLocalDeviceMetadata() API fn.

This function returns device metadata associated with the current device
(i.e., the one on which the code is running).

Bug: 824568, 752273
Change-Id: I08e53e390cf2737bdaff154a9dff2cead9884db0
Reviewed-on: https://chromium-review.googlesource.com/1020069
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Jeremy Klein <jlklein@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553398}

chromeos/services/device_sync/device_sync_impl.cc

@@ -6,6 +6,7 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/no_destructor.h"
+#include "base/optional.h"
 #include "base/time/default_clock.h"
 #include "chromeos/components/proximity_auth/logging/logging.h"
 #include "chromeos/services/device_sync/cryptauth_client_factory_impl.h"
@@ -162,6 +163,21 @@ void DeviceSyncImpl::ForceSyncNow(ForceSyncNowCallback callback) {
   std::move(callback).Run(true /* success */);
 }
 
+void DeviceSyncImpl::GetLocalDeviceMetadata(
+    GetLocalDeviceMetadataCallback callback) {
+  if (status_ != Status::READY) {
+    PA_LOG(WARNING) << "DeviceSyncImpl::GetLocalDeviceMetadata() invoked "
+                    << "before initialization was complete. Cannot return "
+                    << "local device metadata.";
+    std::move(callback).Run(base::nullopt);
+    return;
+  }
+
+  std::string public_key = cryptauth_enrollment_manager_->GetUserPublicKey();
+  DCHECK(!public_key.empty());
+  std::move(callback).Run(GetSyncedDeviceWithPublicKey(public_key));
+}
+
 void DeviceSyncImpl::GetSyncedDevices(GetSyncedDevicesCallback callback) {
   if (status_ != Status::READY) {
     PA_LOG(WARNING) << "DeviceSyncImpl::GetSyncedDevices() invoked before "

chromeos/services/device_sync/device_sync_impl.h

@@ -96,6 +96,7 @@ class DeviceSyncImpl : public mojom::DeviceSync,
                    AddObserverCallback callback) override;
   void ForceEnrollmentNow(ForceEnrollmentNowCallback callback) override;
   void ForceSyncNow(ForceSyncNowCallback callback) override;
+  void GetLocalDeviceMetadata(GetLocalDeviceMetadataCallback callback) override;
   void GetSyncedDevices(GetSyncedDevicesCallback callback) override;
   void SetSoftwareFeatureState(
       const std::string& device_public_key,

chromeos/services/device_sync/device_sync_service_unittest.cc

@@ -6,6 +6,7 @@
 
 #include "base/memory/scoped_refptr.h"
 #include "base/no_destructor.h"
+#include "base/optional.h"
 #include "base/run_loop.h"
 #include "base/test/null_task_runner.h"
 #include "base/test/scoped_task_environment.h"
@@ -45,6 +46,7 @@ namespace {
 const char kTestEmail[] = "example@gmail.com";
 const char kTestGcmDeviceInfoLongDeviceId[] = "longDeviceId";
 const char kTestCryptAuthGCMRegistrationId[] = "cryptAuthRegistrationId";
+const char kLocalDevicePublicKey[] = "localDevicePublicKey";
 const size_t kNumTestDevices = 5u;
 
 const cryptauth::GcmDeviceInfo& GetTestGcmDeviceInfo() {
@@ -61,6 +63,11 @@ cryptauth::RemoteDeviceList GenerateTestRemoteDevices() {
   cryptauth::RemoteDeviceList devices =
       cryptauth::GenerateTestRemoteDevices(kNumTestDevices);
 
+  // One of the synced devices refers to the current (i.e., local) device.
+  // Arbitrarily choose the 0th device as the local one and set its public key
+  // accordingly.
+  devices[0].public_key = kLocalDevicePublicKey;
+
   // Load an empty set of BeaconSeeds for each device.
   // TODO(khorimoto): Adjust device_sync_mojom_traits.h/cc to allow passing
   // devices without BeaconSeeds to be sent across Mojo.
@@ -236,6 +243,7 @@ class FakeCryptAuthEnrollmentManagerFactory
 
     auto instance =
         std::make_unique<cryptauth::FakeCryptAuthEnrollmentManager>();
+    instance->set_user_public_key(kLocalDevicePublicKey);
     instance->set_is_enrollment_valid(device_already_enrolled_in_cryptauth_);
     instance_ = instance.get();
 
@@ -684,6 +692,10 @@ class DeviceSyncServiceTest : public testing::Test {
     // GetSyncedDevices() returns a null list before initialization.
     EXPECT_FALSE(CallGetSyncedDevices());
 
+    // GetLocalDeviceMetadata() returns a null RemoteDevice before
+    // initialization.
+    EXPECT_FALSE(CallGetLocalDeviceMetadata());
+
     // SetSoftwareFeatureState() should return a struct with the special
     // kErrorNotInitialized error code.
     CallSetSoftwareFeatureState(
@@ -745,6 +757,15 @@ class DeviceSyncServiceTest : public testing::Test {
     return last_force_sync_now_result_;
   }
 
+  const base::Optional<cryptauth::RemoteDevice>& CallGetLocalDeviceMetadata() {
+    base::RunLoop run_loop;
+    device_sync_->GetLocalDeviceMetadata(base::BindOnce(
+        &DeviceSyncServiceTest::OnGetLocalDeviceMetadataCompleted,
+        base::Unretained(this), run_loop.QuitClosure()));
+    run_loop.Run();
+    return last_local_device_metadata_result_;
+  }
+
   const base::Optional<cryptauth::RemoteDeviceList>& CallGetSyncedDevices() {
     base::RunLoop run_loop;
     device_sync_->GetSyncedDevices(
@@ -844,6 +865,13 @@ class DeviceSyncServiceTest : public testing::Test {
     std::move(quit_closure).Run();
   }
 
+  void OnGetLocalDeviceMetadataCompleted(
+      base::OnceClosure quit_closure,
+      const base::Optional<cryptauth::RemoteDevice>& local_device_metadata) {
+    last_local_device_metadata_result_ = local_device_metadata;
+    std::move(quit_closure).Run();
+  }
+
   void OnGetSyncedDevicesCompleted(
       base::OnceClosure quit_closure,
       const base::Optional<cryptauth::RemoteDeviceList>& synced_devices) {
@@ -926,6 +954,7 @@ class DeviceSyncServiceTest : public testing::Test {
   bool last_force_enrollment_now_result_;
   bool last_force_sync_now_result_;
   base::Optional<cryptauth::RemoteDeviceList> last_synced_devices_result_;
+  base::Optional<cryptauth::RemoteDevice> last_local_device_metadata_result_;
   std::unique_ptr<base::Optional<std::string>>
       last_set_software_feature_state_response_;
   std::unique_ptr<std::pair<base::Optional<std::string>,
@@ -1039,6 +1068,17 @@ TEST_F(DeviceSyncServiceTest, EnrollAgainAfterInitialization) {
   EXPECT_EQ(1u, fake_device_sync_observer()->num_enrollment_events());
 }
 
+TEST_F(DeviceSyncServiceTest, GetLocalDeviceMetadata) {
+  InitializeServiceSuccessfully();
+
+  const auto& result = CallGetLocalDeviceMetadata();
+  EXPECT_TRUE(result);
+  EXPECT_EQ(kLocalDevicePublicKey, result->public_key);
+  // Note: In GenerateTestRemoteDevices(), the 0th test device is arbitrarily
+  // chosen as the local device.
+  EXPECT_EQ(test_devices()[0], *result);
+}
+
 TEST_F(DeviceSyncServiceTest, SyncedDeviceUpdates) {
   InitializeServiceSuccessfully();
   EXPECT_EQ(1u, fake_device_sync_observer()->num_sync_events());

chromeos/services/device_sync/public/mojom/device_sync.mojom

@@ -144,6 +144,10 @@ interface DeviceSync {
   // device has not yet registered with the back-end, no list is provided.
   GetSyncedDevices() => (array<RemoteDevice>? devices);
 
+  // Returns the RemoteDevice object associated with this device. If this device
+  // has not yet registered with the back-end, no device is provided.
+  GetLocalDeviceMetadata() => (RemoteDevice? local_device);
+
   // Enables or disables the given software feature for the device with the
   // given public key. If |enabled| and |is_exclusive| are both true, this
   // function will enable the feature for the given device and disable the