Fixing the interaction between codec bitrate limit and "b=AS".

webrtc/media/base/mediachannel.h

Index: webrtc/media/base/mediachannel.h
diff --git a/webrtc/media/base/mediachannel.h b/webrtc/media/base/mediachannel.h
index bd1185f7220154f950604fa0cbc12c3d724e0441..61ef648b1aa22cf6b204f9c1c2cd58c2c97ba506 100644
--- a/webrtc/media/base/mediachannel.h
+++ b/webrtc/media/base/mediachannel.h
@@ -93,6 +93,17 @@ static T MinPositive(T a, T b) {
   return std::min(a, b);
 }
 
+template <typename T>
+static T MinNonNegative(T a, T b) {
+  if (a < 0) {
+    return b;
+  }
+  if (b < 0) {
+    return a;
+  }
+  return std::min(a, b);
+}
+
 // Construction-time settings, passed to
 // MediaControllerInterface::Create, and passed on when creating
 // MediaChannels.