Remove FrameTransformerInterface functions using EncodedFrame.

Replaced by the function versions using TransformableFrameInterface
downstream.

Bug: webrtc:11380
Change-Id: Ia4aef84dd76b542ba33287aff6c9151448ed5be6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171864
Commit-Queue: Marina Ciocea <marinaciocea@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Magnus Flodman <mflodman@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31170}

test/mock_frame_transformer.h

@@ -21,12 +21,6 @@ namespace webrtc {
 
 class MockFrameTransformer : public FrameTransformerInterface {
  public:
-  MOCK_METHOD(void,
-              TransformFrame,
-              (std::unique_ptr<video_coding::EncodedFrame>,
-               std::vector<uint8_t>,
-               uint32_t),
-              (override));
   MOCK_METHOD(void,
               Transform,
               (std::unique_ptr<TransformableFrameInterface>),