[Device Discovery] Make DialRegistry a Singleton

chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc

Index: chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc
diff --git a/chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc b/chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc
index 22c65e9f63ca5f2885fc5b6b91b7ac400dd393e9..a42f2e4499d0c149b4ac1343647849870ba5993e 100644
--- a/chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc
+++ b/chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc
@@ -50,6 +50,12 @@ class MockDialRegistry : public DialRegistry {
       : DialRegistry(refresh_interval, expiration, max_devices),
         time_(Time::Now()) {}
 
+  // Returns the mock Dial service.
+  MockDialService& mock_service() { return mock_service_; }
+
+  void set_time(Time time) { time_ = time; }
+
+ protected:
   ~MockDialRegistry() override {
     // Don't let the DialRegistry delete this.
     DialService* tmp = dial_.release();
@@ -57,12 +63,6 @@ class MockDialRegistry : public DialRegistry {
       CHECK_EQ(&mock_service_, tmp);
   }
 
-  // Returns the mock Dial service.
-  MockDialService& mock_service() { return mock_service_; }
-
-  void set_time(Time time) { time_ = time; }
-
- protected:
   base::Time Now() const override { return time_; }
 
   std::unique_ptr<DialService> CreateDialService() override {
@@ -88,8 +88,8 @@ class DialRegistryTest : public testing::Test {
         first_device_("first", GURL("http://127.0.0.1/dd.xml"), Time::Now()),
         second_device_("second", GURL("http://127.0.0.2/dd.xml"), Time::Now()),
         third_device_("third", GURL("http://127.0.0.3/dd.xml"), Time::Now()) {
-    registry_ = base::MakeUnique<MockDialRegistry>(
-        TimeDelta::FromSeconds(1000), TimeDelta::FromSeconds(10), 10);
+    registry_ = scoped_refptr<MockDialRegistry>(new MockDialRegistry(
+        TimeDelta::FromSeconds(1000), TimeDelta::FromSeconds(10), 10));
     registry_->RegisterObserver(&mock_observer_);
     list_with_first_device_.push_back(first_device_);
     list_with_second_device_.push_back(second_device_);
@@ -104,7 +104,7 @@ class DialRegistryTest : public testing::Test {
   }
 
   content::TestBrowserThreadBundle thread_bundle_;
-  std::unique_ptr<MockDialRegistry> registry_;
+  scoped_refptr<MockDialRegistry> registry_;
   MockDialObserver mock_observer_;
   const DialDeviceData first_device_;
   const DialDeviceData second_device_;