Update VideoFramePump to pass un-changed frames to encoders.

remoting/host/host_mock_objects.cc

Index: remoting/host/host_mock_objects.cc
diff --git a/remoting/host/host_mock_objects.cc b/remoting/host/host_mock_objects.cc
index c48517f5eefe6944132a6e2e5184b5372cd21b52..8fdc11e04e39e95b225204cbe843e8c38505e09d 100644
--- a/remoting/host/host_mock_objects.cc
+++ b/remoting/host/host_mock_objects.cc
@@ -13,8 +13,10 @@
 #include "remoting/host/audio_capturer.h"
 #include "remoting/host/input_injector.h"
 #include "remoting/proto/event.pb.h"
+#include "remoting/proto/video.pb.h"
 #include "remoting/protocol/transport.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
 
 namespace remoting {
 
@@ -88,4 +90,15 @@ MockMouseCursorMonitor::MockMouseCursorMonitor() {}
 
 MockMouseCursorMonitor::~MockMouseCursorMonitor() {}
 
+MockVideoEncoder::MockVideoEncoder() {
+}
+
+MockVideoEncoder::~MockVideoEncoder() {
+}
+
+scoped_ptr<VideoPacket> MockVideoEncoder::Encode(
+    const webrtc::DesktopFrame& frame) {
+  return make_scoped_ptr(EncodePtr(frame));
+}
+
 }  // namespace remoting