Remove unused methods in VideoCodingModule.

Also voids ::Codec which always passed.

BUG=
R=stefan@webrtc.org

Review URL: https://codereview.webrtc.org/1464313004 .

Cr-Commit-Position: refs/heads/master@{#11167}
diff --git a/webrtc/modules/video_coding/video_receiver_unittest.cc b/webrtc/modules/video_coding/video_receiver_unittest.cc
index 8fd46ec..820ce9a 100644
--- a/webrtc/modules/video_coding/video_receiver_unittest.cc
+++ b/webrtc/modules/video_coding/video_receiver_unittest.cc
@@ -39,8 +39,7 @@
     const int kMaxPacketAgeToNack = 450;
     receiver_->SetNackSettings(kMaxNackListSize, kMaxPacketAgeToNack, 0);
 
-    memset(&settings_, 0, sizeof(settings_));
-    EXPECT_EQ(0, VideoCodingModule::Codec(kVideoCodecVP8, &settings_));
+    VideoCodingModule::Codec(kVideoCodecVP8, &settings_);
     settings_.plType = kUnusedPayloadType;  // Use the mocked encoder.
     EXPECT_EQ(0, receiver_->RegisterReceiveCodec(&settings_, 1, true));
   }