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 ea94f504423e15c4841ad7feadcab770bbb6e3d9..ebc86d4dd3b3c976ebad1db76e8ad3ad3be92f5b 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -89,6 +89,7 @@
 #include "webrtc/base/socketaddress.h"
 #include "webrtc/base/sslstreamadapter.h"
 #include "webrtc/media/base/mediachannel.h"
+#include "webrtc/media/base/videocapturer.h"
 #include "webrtc/modules/audio_coding/codecs/audio_decoder_factory.h"
 #include "webrtc/p2p/base/portallocator.h"
 
@@ -966,16 +967,32 @@ class PeerConnectionFactoryInterface : public rtc::RefCountInterface {
 
   // Creates a VideoTrackSourceInterface. The new source takes ownership of
   // |capturer|.
-  // TODO(deadbeef): Switch to std::unique_ptr<>, to make this transfership of
-  // ownership more clear.
+  // TODO(deadbeef): Make pure virtual once implemented by chromium subclasses.

[the sun, 2017/02/10 22:00:10]

Do you mean MockPeerConnectionImpl?

[Taylor Brandstetter, 2017/02/11 01:50:08]

Actually... It looks like there aren't any chromium subclasses of
PeerConnectionFactoryInterface. So I'll change this.

[Taylor Brandstetter, 2017/02/11 02:13:22]

Oh, but we DO have mock PC factory implementations internally.

   virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
-      cricket::VideoCapturer* capturer) = 0;
+      std::unique_ptr<cricket::VideoCapturer> capturer) {
+    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.
   virtual rtc::scoped_refptr<VideoTrackSourceInterface> CreateVideoSource(
+      std::unique_ptr<cricket::VideoCapturer> capturer,
+      const MediaConstraintsInterface* constraints) {

[the sun, 2017/02/10 22:00:10]

Since we're clarifying ownership in this CL, what is the contract regarding the
constraints? Is it just borrowed in this call or is it expected to outlive the
PC object?

[Taylor Brandstetter, 2017/02/11 01:50:08]

It's only used within this method, so it's not required to outlive the PC. I'll
add a comment.

+    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.