dbus: Make Bus::is_connected() mockable

It's currently not possible to have a unit test that triggers
Bus::is_connected() because it always returns false. This is currently
needed by the Bluetooth dispatcher (btdispatch) in Chrome OS.

Bug: 866704
Change-Id: I04f7e8a22792886d421479c1c7c621eeb27d3a2a
Reviewed-on: https://chromium-review.googlesource.com/1175216
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Commit-Queue: Sonny Sasaka <sonnysasaka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583543}

dbus/bus.cc

@@ -997,6 +997,10 @@ std::string Bus::GetConnectionName() {
   return dbus_bus_get_unique_name(connection_);
 }
 
+bool Bus::IsConnected() {
+  return connection_ != nullptr;
+}
+
 dbus_bool_t Bus::OnAddWatch(DBusWatch* raw_watch) {
   AssertOnDBusThread();
 

dbus/bus.h

@@ -601,7 +601,7 @@ class CHROME_DBUS_EXPORT Bus : public base::RefCountedThreadSafe<Bus> {
   std::string GetConnectionName();
 
   // Returns true if the bus is connected to D-Bus.
-  bool is_connected() { return connection_ != nullptr; }
+  virtual bool IsConnected();
 
  protected:
   // This is protected, so we can define sub classes.

dbus/bus_unittest.cc

@@ -402,14 +402,14 @@ TEST(BusTest, GetConnectionName) {
   scoped_refptr<Bus> bus = new Bus(options);
 
   // Connection name is empty since bus is not connected.
-  EXPECT_FALSE(bus->is_connected());
+  EXPECT_FALSE(bus->IsConnected());
   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_TRUE(bus->IsConnected());
   EXPECT_FALSE(bus->GetConnectionName().empty());
 
   // Shut down synchronously.

dbus/exported_object.cc

@@ -280,7 +280,7 @@ void ExportedObject::OnMethodCompleted(std::unique_ptr<MethodCall> method_call,
 
   // Check if the bus is still connected. If the method takes long to
   // complete, the bus may be shut down meanwhile.
-  if (!bus_->is_connected())
+  if (!bus_->IsConnected())
     return;
 
   if (!response) {

dbus/mock_bus.h

@@ -73,6 +73,7 @@ class MockBus : public Bus {
   MOCK_METHOD0(HasDBusThread, bool());
   MOCK_METHOD0(AssertOnOriginThread, void());
   MOCK_METHOD0(AssertOnDBusThread, void());
+  MOCK_METHOD0(IsConnected, bool());
 
  protected:
   ~MockBus() override;

dbus/object_proxy.cc

@@ -288,7 +288,7 @@ void ObjectProxy::WaitForServiceToBeAvailable(
 void ObjectProxy::Detach() {
   bus_->AssertOnDBusThread();
 
-  if (bus_->is_connected())
+  if (bus_->IsConnected())
     bus_->RemoveFilterFunction(&ObjectProxy::HandleMessageThunk, this);
 
   for (const auto& match_rule : match_rules_) {