Cleanup usage of scoped_ptr<> in remoting for C++11

remoting/host/fake_desktop_environment.cc

Index: remoting/host/fake_desktop_environment.cc
diff --git a/remoting/host/fake_desktop_environment.cc b/remoting/host/fake_desktop_environment.cc
index f399ae853103e46150dacc481b2543d5ae2d4f0b..bdf0d0a0d0b498af367cd30837ad42cca8a862ed 100644
--- a/remoting/host/fake_desktop_environment.cc
+++ b/remoting/host/fake_desktop_environment.cc
@@ -44,7 +44,7 @@ FakeDesktopEnvironment::~FakeDesktopEnvironment() {}
 
 // DesktopEnvironment implementation.
 scoped_ptr<AudioCapturer> FakeDesktopEnvironment::CreateAudioCapturer() {
-  return scoped_ptr<AudioCapturer>();
+  return nullptr;
 }
 
 scoped_ptr<InputInjector> FakeDesktopEnvironment::CreateInputInjector() {
@@ -60,7 +60,7 @@ FakeDesktopEnvironment::CreateVideoCapturer() {
   scoped_ptr<FakeDesktopCapturer> result(new FakeDesktopCapturer());
   if (!frame_generator_.is_null())
     result->set_frame_generator(frame_generator_);
-  return result.PassAs<webrtc::DesktopCapturer>();
+  return result.Pass();
 }
 
 scoped_ptr<webrtc::MouseCursorMonitor>
@@ -76,7 +76,7 @@ void FakeDesktopEnvironment::SetCapabilities(const std::string& capabilities) {}
 
 scoped_ptr<GnubbyAuthHandler> FakeDesktopEnvironment::CreateGnubbyAuthHandler(
     protocol::ClientStub* client_stub) {
-  return scoped_ptr<GnubbyAuthHandler>();
+  return nullptr;
 }
 
 FakeDesktopEnvironmentFactory::FakeDesktopEnvironmentFactory() {}
@@ -87,7 +87,7 @@ scoped_ptr<DesktopEnvironment> FakeDesktopEnvironmentFactory::Create(
     base::WeakPtr<ClientSessionControl> client_session_control) {
   scoped_ptr<FakeDesktopEnvironment> result(new FakeDesktopEnvironment());
   result->set_frame_generator(frame_generator_);
-  return result.PassAs<DesktopEnvironment>();
+  return result.Pass();
 }
 
 void FakeDesktopEnvironmentFactory::SetEnableCurtaining(bool enable) {}