This is related to https://code.google.com/p/webrtc/issues/detail?id=1341

BUG=1341
R=mallinath@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/2225004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@4761 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/modules/video_render/mac/video_render_nsopengl.mm b/modules/video_render/mac/video_render_nsopengl.mm
index 3410da0..0659496 100644
--- a/modules/video_render/mac/video_render_nsopengl.mm
+++ b/modules/video_render/mac/video_render_nsopengl.mm
@@ -64,7 +64,7 @@
 
 int VideoChannelNSOpenGL::ChangeContext(NSOpenGLContext *nsglContext)
 {
-    _owner->UnlockAGLCntx();
+    _owner->LockAGLCntx();
 
     _nsglContext = nsglContext;
     [_nsglContext makeCurrentContext];