Hook up ProximityAuthSystem in EasyUnlockService.

components/proximity_auth/remote_device_life_cycle_impl_unittest.cc

Index: components/proximity_auth/remote_device_life_cycle_impl_unittest.cc
diff --git a/components/proximity_auth/remote_device_life_cycle_impl_unittest.cc b/components/proximity_auth/remote_device_life_cycle_impl_unittest.cc
index 77e3aa36959a414efa5c07a0988ac19cb0d83cde..ec5e4c654a4f443f6395433a4ea51307a3fde280 100644
--- a/components/proximity_auth/remote_device_life_cycle_impl_unittest.cc
+++ b/components/proximity_auth/remote_device_life_cycle_impl_unittest.cc
@@ -92,8 +92,13 @@ class FakeConnectionFinder : public ConnectionFinder {
 
 class FakeAuthenticator : public Authenticator {
  public:
-  FakeAuthenticator() {}
-  ~FakeAuthenticator() override {}
+  FakeAuthenticator(Connection* connection) : connection_(connection) {}
+  ~FakeAuthenticator() override {
+    // This object should be destroyed immediately after authentication is
+    // complete in order not to outlive the underlying connection.
+    EXPECT_FALSE(callback_.is_null());
+    EXPECT_EQ(std::string(), connection_->remote_device().public_key);
+  }
 
   void OnAuthenticationResult(Authenticator::Result result) {
     ASSERT_FALSE(callback_.is_null());
@@ -110,6 +115,8 @@ class FakeAuthenticator : public Authenticator {
     callback_ = callback;
   }
 
+  Connection* connection_;
+
   AuthenticationCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeAuthenticator);
@@ -136,7 +143,9 @@ class TestableRemoteDeviceLifeCycleImpl : public RemoteDeviceLifeCycleImpl {
   }
 
   scoped_ptr<Authenticator> CreateAuthenticator() override {
-    scoped_ptr<FakeAuthenticator> scoped_authenticator(new FakeAuthenticator());
+    EXPECT_TRUE(connection_finder_);
+    scoped_ptr<FakeAuthenticator> scoped_authenticator(
+        new FakeAuthenticator(connection_finder_->connection()));
     authenticator_ = scoped_authenticator.get();
     return scoped_authenticator.Pass();
   }