Revert "Add fine grained dropped video frames counters on sending side"

This reverts commit 4b1a363e4c238f2e1ec2d8a9ce1f819f59d710ce.

Reason for revert: Breaks dependent android projects.

Original change's description:
> Add fine grained dropped video frames counters on sending side
> 
> 4 new counters added to SendStatisticsProxy and reported to UMA and logs.
> 
> Bug: webrtc:8355
> Change-Id: Idf9b8dfc295c92821e058a97cb3894dc6a446082
> Reviewed-on: https://webrtc-review.googlesource.com/12260
> Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
> Reviewed-by: Stefan Holmer <stefan@webrtc.org>
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#20347}

TBR=deadbeef@webrtc.org,ilnik@webrtc.org,sprang@webrtc.org,stefan@webrtc.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: webrtc:8355
Change-Id: I59b02f4eb77abad7ff1fbcbfa61844918c95d723
Reviewed-on: https://webrtc-review.googlesource.com/14500
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20378}
diff --git a/modules/video_coding/generic_encoder_unittest.cc b/modules/video_coding/generic_encoder_unittest.cc
index 9c879e3..90d3c05 100644
--- a/modules/video_coding/generic_encoder_unittest.cc
+++ b/modules/video_coding/generic_encoder_unittest.cc
@@ -27,8 +27,7 @@
 
 class FakeEncodedImageCallback : public EncodedImageCallback {
  public:
-  FakeEncodedImageCallback()
-      : last_frame_was_timing_(false), num_frames_dropped_(0) {}
+  FakeEncodedImageCallback() : last_frame_was_timing_(false) {}
   Result OnEncodedImage(const EncodedImage& encoded_image,
                         const CodecSpecificInfo* codec_specific_info,
                         const RTPFragmentationHeader* fragmentation) override {
@@ -37,15 +36,10 @@
     return Result(Result::OK);
   };
 
-  void OnDroppedFrame(DropReason reason) override { ++num_frames_dropped_; }
-
   bool WasTimingFrame() { return last_frame_was_timing_; }
 
-  size_t GetNumFramesDropped() { return num_frames_dropped_; }
-
  private:
   bool last_frame_was_timing_;
-  size_t num_frames_dropped_;
 };
 
 enum class FrameType {
@@ -196,34 +190,5 @@
   EXPECT_FALSE(sink.WasTimingFrame());
 }
 
-TEST(TestVCMEncodedFrameCallback, NotifiesAboutDroppedFrames) {
-  EncodedImage image;
-  CodecSpecificInfo codec_specific;
-  const int64_t timestamp1 = 100;
-  const int64_t timestamp2 = 110;
-  const int64_t timestamp3 = 120;
-  const int64_t timestamp4 = 130;
-  codec_specific.codecType = kVideoCodecGeneric;
-  codec_specific.codecSpecific.generic.simulcast_idx = 0;
-  FakeEncodedImageCallback sink;
-  VCMEncodedFrameCallback callback(&sink, nullptr);
-  callback.OnEncodeStarted(timestamp1, 0);
-  EXPECT_EQ(0u, sink.GetNumFramesDropped());
-  image.capture_time_ms_ = timestamp1;
-  callback.OnEncodedImage(image, &codec_specific, nullptr);
-  callback.OnEncodeStarted(timestamp2, 0);
-  // No OnEncodedImageCall for timestamp2. Yet, at this moment it's not known
-  // that frame with timestamp2 was dropped.
-  EXPECT_EQ(0u, sink.GetNumFramesDropped());
-  callback.OnEncodeStarted(timestamp3, 0);
-  image.capture_time_ms_ = timestamp3;
-  callback.OnEncodedImage(image, &codec_specific, nullptr);
-  EXPECT_EQ(1u, sink.GetNumFramesDropped());
-  callback.OnEncodeStarted(timestamp4, 0);
-  image.capture_time_ms_ = timestamp4;
-  callback.OnEncodedImage(image, &codec_specific, nullptr);
-  EXPECT_EQ(1u, sink.GetNumFramesDropped());
-}
-
 }  // namespace test
 }  // namespace webrtc