PlzNavigate: Refactor unit test helper functions

content/test/browser_side_navigation_test_utils.cc

+// Copyright (c) 2014 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 "content/test/browser_side_navigation_test_utils.h"
+
+#include "base/command_line.h"
+#include "base/guid.h"
+#include "base/lazy_instance.h"
+#include "content/browser/streams/stream.h"
+#include "content/browser/streams/stream_registry.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/stream_handle.h"
+#include "content/public/common/content_switches.h"
+#include "content/test/test_navigation_url_loader_factory.h"
+
+namespace content {
+
+namespace {
+
+// PlzNavigate
+// A UI thread singleton helper class for browser side navigations. When browser
+// side navigations are enabled, initialize this class before doing any
+// operation that may start a navigation request on the UI thread. Use TearDown
+// at the end of the test.
+class BrowserSideNavigationTestUtils {
+ public:
+  BrowserSideNavigationTestUtils()
+      : stream_registry_(new StreamRegistry),
+        loader_factory_(new TestNavigationURLLoaderFactory) {
+  }
+
+  ~BrowserSideNavigationTestUtils() {}
+  StreamRegistry* stream_registry() { return stream_registry_.get();}
+
+ private:
+  scoped_ptr<StreamRegistry> stream_registry_;
+  scoped_ptr<TestNavigationURLLoaderFactory> loader_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserSideNavigationTestUtils);
+};
+
+base::LazyInstance<scoped_ptr<BrowserSideNavigationTestUtils>>
+    browser_side_navigation_test_utils;
+
+}  // namespace
+
+void BrowserSideNavigationSetUp() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  browser_side_navigation_test_utils.Get().reset(
+      new BrowserSideNavigationTestUtils);
+}
+
+void BrowserSideNavigationTearDown() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  browser_side_navigation_test_utils.Get().reset(nullptr);
+}
+
+scoped_ptr<StreamHandle> MakeEmptyStream() {
+  GURL url(std::string(url::kBlobScheme) + "://" + base::GenerateGUID());
+  StreamRegistry* stream_registry =
+      browser_side_navigation_test_utils.Get()->stream_registry();
+  scoped_refptr<Stream> stream(new Stream(stream_registry, NULL, url));
+  stream->Finalize();
+  return stream->CreateHandle();
+}
+
+void EnableBrowserSideNavigation() {
+  CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kEnableBrowserSideNavigation);
+}
+
+}  // namespace content