Replace the explicit *VDA::Set{CGL,Egl,Glx}Context() methods with ctor params.

content/common/gpu/media/mac_video_decode_accelerator.mm

Index: content/common/gpu/media/mac_video_decode_accelerator.mm
diff --git a/content/common/gpu/media/mac_video_decode_accelerator.mm b/content/common/gpu/media/mac_video_decode_accelerator.mm
index 7aa9c6c66d69a07b860cf79ad0ea3fd43e238bdb..94b67808df60cf78ecfa23be8ef778adb97cbc66 100644
--- a/content/common/gpu/media/mac_video_decode_accelerator.mm
+++ b/content/common/gpu/media/mac_video_decode_accelerator.mm
@@ -93,17 +93,12 @@ static bool BindImageToTexture(CGLContextObj context,
 }
 
 MacVideoDecodeAccelerator::MacVideoDecodeAccelerator(
-    media::VideoDecodeAccelerator::Client* client)
+    CGLContextObj cgl_context, media::VideoDecodeAccelerator::Client* client)
     : client_(client),
-      cgl_context_(NULL),
+      cgl_context_(cgl_context),
       did_build_config_record_(false) {
 }
 
-void MacVideoDecodeAccelerator::SetCGLContext(CGLContextObj cgl_context) {
-  DCHECK(CalledOnValidThread());
-  cgl_context_ = cgl_context;
-}
-
 bool MacVideoDecodeAccelerator::Initialize(media::VideoCodecProfile profile) {
   DCHECK(CalledOnValidThread());