Switching some interfaces to use std::unique_ptr<>.

webrtc/api/peerconnectioninterface.h

Index: webrtc/api/peerconnectioninterface.h
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index 2a22258a0a2ab80c51e6c8572b4e799f4c87368b..0c9198cd01574af4efe9ddc68895fe679c070262 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -90,6 +90,7 @@
 #include "webrtc/base/socketaddress.h"
 #include "webrtc/base/sslstreamadapter.h"
 #include "webrtc/media/base/mediachannel.h"
+#include "webrtc/media/base/videocapturer.h"
 #include "webrtc/p2p/base/portallocator.h"
 
 namespace rtc {
@@ -966,16 +967,37 @@ class PeerConnectionFactoryInterface : public rtc::RefCountInterface {
 
   // Creates a VideoTrackSourceInterface. The new source takes ownership of

[nisse-webrtc, 2017/02/13 08:25:58]

You could drop the ownership comment here too, since it's implied by unique_ptr.

[Taylor Brandstetter, 2017/02/13 17:47:45]

Done.

   // |capturer|.
-  // TODO(deadbeef): Switch to std::unique_ptr<>, to make this transfership of
-  // ownership more clear.
+  // TODO(deadbeef): Make pure virtual once downstream mock PC factory classes
+  // are updated.
   virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
-      cricket::VideoCapturer* capturer) = 0;
+      std::unique_ptr<cricket::VideoCapturer> capturer) {

[nisse-webrtc, 2017/02/13 08:25:58]

We should aim to kill cricket::VideoCapturer. As far as I'm aware, it's
now used only by the layers of wrappers around webrtc's own platform specific
capturers. Which should should be refactored into to implementing
VideoTrackSourceInterface directly.

(Not an objection to this change, it's just annoying that we still have this
method).

[Taylor Brandstetter, 2017/02/13 17:47:45]

Added TODO.

+    return nullptr;
+  }
+
   // A video source creator that allows selection of resolution and frame rate.
   // |constraints| decides video resolution and frame rate but can be NULL.
   // In the NULL case, use the version above.
+  //
+  // |constraints| is only used for the invocation of this method, and can
+  // safely be destroyed afterwards.
+  virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
+      std::unique_ptr<cricket::VideoCapturer> capturer,
+      const MediaConstraintsInterface* constraints) {
+    return nullptr;
+  }
+
+  // Deprecated; please use the versions that take unique_ptrs above.
+  // TODO(deadbeef): Remove these once safe to do so.
+  virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
+      cricket::VideoCapturer* capturer) {
+    return CreateVideoSource(std::unique_ptr<cricket::VideoCapturer>(capturer));
+  }
   virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
       cricket::VideoCapturer* capturer,
-      const MediaConstraintsInterface* constraints) = 0;
+      const MediaConstraintsInterface* constraints) {
+    return CreateVideoSource(std::unique_ptr<cricket::VideoCapturer>(capturer),
+                             constraints);
+  }
 
   // Creates a new local VideoTrack. The same |source| can be used in several
   // tracks.