Add thread annotations to Call API.

Also constified a lot of pointers and reordered members to make
protected members more grouped together.

R=kjellander@webrtc.org, stefan@webrtc.org
BUG=2770

Review URL: https://webrtc-codereview.appspot.com/15399004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5998 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/video/video_send_stream.cc b/video/video_send_stream.cc
index 2680b09..e6e683a 100644
--- a/video/video_send_stream.cc
+++ b/video/video_send_stream.cc
@@ -37,7 +37,8 @@
       codec_lock_(CriticalSectionWrapper::CreateCriticalSection()),
       config_(config),
       external_codec_(NULL),
-      channel_(-1) {
+      channel_(-1),
+      stats_proxy_(new SendStatisticsProxy(config, this)) {
   video_engine_base_ = ViEBase::GetInterface(video_engine);
   video_engine_base_->CreateChannel(channel_, base_channel);
   assert(channel_ != -1);
@@ -142,8 +143,6 @@
     codec_->SuspendBelowMinBitrate(channel_);
   }
 
-  stats_proxy_.reset(new SendStatisticsProxy(config, this));
-
   rtp_rtcp_->RegisterSendChannelRtcpStatisticsCallback(channel_,
                                                        stats_proxy_.get());
   rtp_rtcp_->RegisterSendChannelRtpStatisticsCallback(channel_,