scanning: add unit tests for LorgnetteManagerClient

Add the first set of unit tests for LorgnetteManagerClient. These
tests cover the ListScanners() and GetScannerCapabilities() methods, as
well as several failure cases for the kScanStatusChangedSignal. Still to
be done are tests for the StartScan method. Also do some minor cleanup
of lorgnette_manager_client.cc.

Bug: b:169573779
Change-Id: I64ff7f31430db62fe21e7632db3bd2bb7be8547e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2495514Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Paul Moy <pmoy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821768}

chromeos/dbus/BUILD.gn

@@ -190,6 +190,7 @@ source_set("unit_tests") {
     "//chromeos/dbus/dlcservice:test_support",
     "//chromeos/dbus/hermes:test_support",
     "//chromeos/dbus/ip_peripheral:test_support",
+    "//chromeos/dbus/lorgnette_manager:test_support",
     "//chromeos/dbus/power:power_manager_proto",
     "//chromeos/dbus/power:test_support",
     "//chromeos/dbus/session_manager",

chromeos/dbus/lorgnette_manager/BUILD.gn

@@ -25,6 +25,20 @@ component("lorgnette_manager") {
   ]
 }
 
+source_set("test_support") {
+  testonly = true
+  public_deps = [ ":lorgnette_manager" ]
+  deps = [
+    ":lorgnette_proto",
+    "//base",
+    "//base/test:test_support",
+    "//dbus:test_support",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
+  sources = [ "lorgnette_manager_client_unittest.cc" ]
+}
+
 proto_library("lorgnette_proto") {
   sources =
       [ "//third_party/cros_system_api/dbus/lorgnette/lorgnette_service.proto" ]

chromeos/dbus/lorgnette_manager/lorgnette_manager_client.cc

@@ -15,7 +15,6 @@
 #include "base/files/scoped_file.h"
 #include "base/location.h"
 #include "base/logging.h"
-#include "base/macros.h"
 #include "base/optional.h"
 #include "base/sequence_checker.h"
 #include "base/task/post_task.h"
@@ -65,7 +64,6 @@ class LorgnetteManagerClientImpl : public LorgnetteManagerClient {
             weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
   }
 
-  // LorgnetteManagerClient override.
   void StartScan(
       const std::string& device_name,
       const lorgnette::ScanSettings& settings,
@@ -122,6 +120,8 @@ class LorgnetteManagerClientImpl : public LorgnetteManagerClient {
         base::OnceCallback<void(base::Optional<std::string> data)>;
 
     ScanDataReader() = default;
+    ScanDataReader(const ScanDataReader&) = delete;
+    ScanDataReader& operator=(const ScanDataReader&) = delete;
 
     // Creates a pipe to read the scan data from the D-Bus service.
     // Returns a write-side FD.
@@ -175,7 +175,6 @@ class LorgnetteManagerClientImpl : public LorgnetteManagerClient {
     CompletionCallback callback_;
 
     base::WeakPtrFactory<ScanDataReader> weak_ptr_factory_{this};
-    DISALLOW_COPY_AND_ASSIGN(ScanDataReader);
   };
 
   // The state tracked for an in-progress scan job.

chromeos/dbus/lorgnette_manager/lorgnette_manager_client.h

@@ -62,6 +62,8 @@ class COMPONENT_EXPORT(LORGNETTE_MANAGER) LorgnetteManagerClient
   static std::unique_ptr<LorgnetteManagerClient> Create();
 
  protected:
+  friend class LorgnetteManagerClientTest;
+
   // Create() should be used instead.
   LorgnetteManagerClient();
 };