Revert 7151 "Revert 7114 "Expose VideoEncoders with webrtc/video_encoder.h.""

Re-lands r7114 after landing r7204 to adress the compile error causing
the rollback in r7151.

BUG=3070
TBR=henrikg@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/28489004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7207 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/test/fake_encoder.cc b/webrtc/test/fake_encoder.cc
index ecd3dd8..9551c82 100644
--- a/webrtc/test/fake_encoder.cc
+++ b/webrtc/test/fake_encoder.cc
@@ -12,6 +12,8 @@
 
 #include "testing/gtest/include/gtest/gtest.h"
 
+#include "webrtc/modules/video_coding/codecs/interface/video_codec_interface.h"
+
 namespace webrtc {
 namespace test {