dbus: expose bus connection unique name

Add an API to Bus class to expose the unique name of the bus connection.
The function will return an empty string if bus connection is not
established.

BUG=chromium:507718
TEST=unittest

Review URL: https://codereview.chromium.org/1222073003

Cr-Commit-Position: refs/heads/master@{#337732}

1 files changed, 20 insertions, 0 deletions

diff --git a/dbus/bus_unittest.cc b/dbus/bus_unittest.cc
index 1e84fa5..27d9bb2 100644
--- a/dbus/bus_unittest.cc
+++ b/dbus/bus_unittest.cc
@@ -394,4 +394,24 @@ TEST(BusTest, ListenForServiceOwnerChange) {
   EXPECT_TRUE(bus->shutdown_completed());
 }
 
+TEST(BusTest, GetConnectionName) {
+  Bus::Options options;
+  scoped_refptr<Bus> bus = new Bus(options);
+
+  // Connection name is empty since bus is not connected.
+  EXPECT_FALSE(bus->is_connected());
+  EXPECT_TRUE(bus->GetConnectionName().empty());
+
+  // Connect bus to D-Bus.
+  bus->Connect();
+
+  // Connection name is not empty after connection is established.
+  EXPECT_TRUE(bus->is_connected());
+  EXPECT_FALSE(bus->GetConnectionName().empty());
+
+  // Shut down synchronously.
+  bus->ShutdownAndBlock();
+  EXPECT_TRUE(bus->shutdown_completed());
+}
+
 }  // namespace dbus