Add experiment: SkipEncodingUnusedStreams

BUG=
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/7889004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5514 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/experiments.h b/webrtc/experiments.h
index f6d54a0..309c7b4 100644
--- a/webrtc/experiments.h
+++ b/webrtc/experiments.h
@@ -28,5 +28,14 @@
 
   uint32_t min_rate;
 };
+
+struct SkipEncodingUnusedStreams {
+  SkipEncodingUnusedStreams() : enabled(false) {}
+  explicit SkipEncodingUnusedStreams(bool set_enabled)
+    : enabled(set_enabled) {}
+  virtual ~SkipEncodingUnusedStreams() {}
+
+  const bool enabled;
+};
 }  // namespace webrtc
 #endif  // WEBRTC_EXPERIMENTS_H_