Added CupsProxyServiceDelegate

Added delegate provides the service with necessary Chrome printing stack
dependencies, i.e. hooks to the CupsPrintersManager/PrinterConfigurer.

Also adds a helpful fake for unit testing.

Bug: chromium:945409
Test: none
Change-Id: I6bb02592993fd6bb22b33240b2ae8d6e332304cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1621326
Commit-Queue: Luum Habtemariam <luum@chromium.org>
Reviewed-by: Sean Kau <skau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663942}

chrome/services/cups_proxy/BUILD.gn

@@ -12,6 +12,8 @@ source_set("cups_proxy") {
   sources = [
     "cups_proxy_service.cpp",
     "cups_proxy_service.h",
+    "cups_proxy_service_delegate.cc",
+    "cups_proxy_service_delegate.h",
   ]
 
   deps = [
@@ -32,3 +34,15 @@ source_set("cups_proxy") {
     "//printing",
   ]
 }
+
+static_library("test_support") {
+  testonly = true
+  sources = [
+    "fake_cups_proxy_service_delegate.cc",
+    "fake_cups_proxy_service_delegate.h",
+  ]
+
+  public_deps = [
+    ":cups_proxy",
+  ]
+}

chrome/services/cups_proxy/DEPS

+include_rules = [
+  "+chromeos/printing",
+]

chrome/services/cups_proxy/cups_proxy_service_delegate.cc

+// Copyright 2019 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.
+
+#include "chrome/services/cups_proxy/cups_proxy_service_delegate.h"
+
+#include <memory>
+#include <string>
+
+#include "base/memory/weak_ptr.h"
+
+namespace chromeos {
+namespace printing {
+
+CupsProxyServiceDelegate::CupsProxyServiceDelegate() : weak_factory_(this) {}
+CupsProxyServiceDelegate::~CupsProxyServiceDelegate() = default;
+
+base::WeakPtr<CupsProxyServiceDelegate> CupsProxyServiceDelegate::GetWeakPtr() {
+  return weak_factory_.GetWeakPtr();
+}
+
+}  // namespace printing
+}  // namespace chromeos

chrome/services/cups_proxy/cups_proxy_service_delegate.h

+// Copyright 2019 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 CHROME_SERVICES_CUPS_PROXY_CUPS_PROXY_SERVICE_DELEGATE_H_
+#define CHROME_SERVICES_CUPS_PROXY_CUPS_PROXY_SERVICE_DELEGATE_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/weak_ptr.h"
+#include "chromeos/printing/printer_configuration.h"
+
+namespace chromeos {
+namespace printing {
+
+using PrinterSetupCallback = base::OnceCallback<void(bool)>;
+
+// This delegate grants the CupsProxyService access to the Chrome printing
+// stack. This class can be created anywhere but must be accessed from a
+// sequenced context.
+class CupsProxyServiceDelegate {
+ public:
+  CupsProxyServiceDelegate();
+  virtual ~CupsProxyServiceDelegate();
+
+  // Exposing |weak_factory_|.GetWeakPtr method. Needed to share delegate with
+  // CupsProxyService internal managers.
+  base::WeakPtr<CupsProxyServiceDelegate> GetWeakPtr();
+
+  virtual std::vector<chromeos::Printer> GetPrinters() = 0;
+  virtual base::Optional<chromeos::Printer> GetPrinter(
+      const std::string& id) = 0;
+  virtual bool IsPrinterInstalled(const Printer& printer) = 0;
+
+  // |cb| will be run on this delegate's sequenced context.
+  virtual void SetupPrinter(const Printer& printer,
+                            PrinterSetupCallback cb) = 0;
+
+ private:
+  base::WeakPtrFactory<CupsProxyServiceDelegate> weak_factory_;
+};
+
+}  // namespace printing
+}  // namespace chromeos
+
+#endif  // CHROME_SERVICES_CUPS_PROXY_CUPS_PROXY_SERVICE_DELEGATE_H_

chrome/services/cups_proxy/fake_cups_proxy_service_delegate.cc

+// Copyright 2019 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.
+
+#include "chrome/services/cups_proxy/fake_cups_proxy_service_delegate.h"
+
+namespace chromeos {
+namespace printing {
+
+std::vector<chromeos::Printer> FakeCupsProxyServiceDelegate::GetPrinters() {
+  return {};
+}
+
+base::Optional<chromeos::Printer> FakeCupsProxyServiceDelegate::GetPrinter(
+    const std::string& id) {
+  return base::nullopt;
+}
+
+bool FakeCupsProxyServiceDelegate::IsPrinterInstalled(const Printer& printer) {
+  return false;
+}
+
+void FakeCupsProxyServiceDelegate::SetupPrinter(const Printer& printer,
+                                                PrinterSetupCallback cb) {}
+
+}  // namespace printing
+}  // namespace chromeos

chrome/services/cups_proxy/fake_cups_proxy_service_delegate.h

+// Copyright 2019 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 CHROME_SERVICES_CUPS_PROXY_FAKE_CUPS_PROXY_SERVICE_DELEGATE_H_
+#define CHROME_SERVICES_CUPS_PROXY_FAKE_CUPS_PROXY_SERVICE_DELEGATE_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "chrome/services/cups_proxy/cups_proxy_service_delegate.h"
+#include "chromeos/printing/printer_configuration.h"
+
+namespace chromeos {
+namespace printing {
+
+// Fake implementation for use in unit_tests.
+class FakeCupsProxyServiceDelegate : public CupsProxyServiceDelegate {
+ public:
+  FakeCupsProxyServiceDelegate() = default;
+  ~FakeCupsProxyServiceDelegate() override = default;
+
+  // CupsProxyServiceDelegate overrides.
+  std::vector<chromeos::Printer> GetPrinters() override;
+  base::Optional<chromeos::Printer> GetPrinter(const std::string& id) override;
+  bool IsPrinterInstalled(const Printer& printer) override;
+  void SetupPrinter(const Printer& printer, PrinterSetupCallback cb) override;
+};
+
+}  // namespace printing
+}  // namespace chromeos
+
+#endif  // CHROME_SERVICES_CUPS_PROXY_FAKE_CUPS_PROXY_SERVICE_DELEGATE_H_