Skip encoding in fake VP8 encoder.

Broke memcheck, FakeEncoder::Encode doesn't produce valid VP8 frames.

BUG=3424
R=stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/13899004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6652 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/video/video_send_stream_tests.cc

@@ -1419,6 +1419,14 @@ TEST_F(VideoSendStreamTest, EncoderSetupPropagatesVp8Config) {
              "new encoder settings.";
     }
 
+    int32_t Encode(
+        const I420VideoFrame& input_image,
+        const CodecSpecificInfo* codec_specific_info,
+        const std::vector<VideoFrameType>* frame_types) {
+      // Silently skip the encode, FakeEncoder::Encode doesn't produce VP8.
+      return 0;
+    }
+
     virtual const void* GetEncoderSettings() OVERRIDE { return &vp8_settings_; }
 
     VideoCodecVP8 vp8_settings_;