Unify FrameType and VideoFrameType.

Prevents some heap allocation and frame-type conversion since interfaces
mismatch. Also it's less confusing to have one type for this.

BUG=webrtc:5042
R=magjed@webrtc.org, mflodman@webrtc.org, henrik.lundin@webrtc.org, solenberg@webrtc.org, stefan@webrtc.org

Review URL: https://codereview.webrtc.org/1371043003

Cr-Commit-Position: refs/heads/master@{#10320}

webrtc/modules/video_coding/codecs/interface/mock/mock_video_codec_interface.h

@@ -35,7 +35,7 @@ class MockVideoEncoder : public VideoEncoder {
   MOCK_METHOD3(Encode,
                int32_t(const VideoFrame& inputImage,
                        const CodecSpecificInfo* codecSpecificInfo,
-                       const std::vector<VideoFrameType>* frame_types));
+                       const std::vector<FrameType>* frame_types));
   MOCK_METHOD1(RegisterEncodeCompleteCallback,
                int32_t(EncodedImageCallback* callback));
   MOCK_METHOD0(Release, int32_t());