Revert of [Cast] Software encoder support for varying video frame sizes.

media/cast/sender/video_encoder_impl.cc

Index: media/cast/sender/video_encoder_impl.cc
diff --git a/media/cast/sender/video_encoder_impl.cc b/media/cast/sender/video_encoder_impl.cc
index 4efe32044a80c2d299691bbe6cb570e379935500..52ece8ca22e4d05a922516de704e161f91b6bb29 100644
--- a/media/cast/sender/video_encoder_impl.cc
+++ b/media/cast/sender/video_encoder_impl.cc
@@ -54,8 +54,7 @@
 
 VideoEncoderImpl::VideoEncoderImpl(
     scoped_refptr<CastEnvironment> cast_environment,
-    const VideoSenderConfig& video_config,
-    const CastInitializationCallback& initialization_cb)
+    const VideoSenderConfig& video_config)
     : cast_environment_(cast_environment) {
   CHECK(cast_environment_->HasVideoThread());
   if (video_config.codec == CODEC_VIDEO_VP8) {
@@ -76,15 +75,6 @@
   dynamic_config_.key_frame_requested = false;
   dynamic_config_.latest_frame_id_to_reference = kStartFrameId;
   dynamic_config_.bit_rate = video_config.start_bitrate;
-
-  if (!initialization_cb.is_null()) {
-    cast_environment_->PostTask(
-        CastEnvironment::MAIN,
-        FROM_HERE,
-        base::Bind(initialization_cb,
-                   encoder_.get() ? STATUS_VIDEO_INITIALIZED :
-                                    STATUS_UNSUPPORTED_VIDEO_CODEC));
-  }
 }
 
 VideoEncoderImpl::~VideoEncoderImpl() {
@@ -98,20 +88,11 @@
   }
 }
 
-bool VideoEncoderImpl::CanEncodeVariedFrameSizes() const {
-  // Both the VP8Encoder and FakeSoftwareVideoEncoder support calls to
-  // EncodeVideoFrame() with different frame sizes.
-  return true;
-}
-
 bool VideoEncoderImpl::EncodeVideoFrame(
     const scoped_refptr<media::VideoFrame>& video_frame,
     const base::TimeTicks& reference_time,
     const FrameEncodedCallback& frame_encoded_callback) {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
-  DCHECK(!video_frame->visible_rect().IsEmpty());
-  DCHECK(!frame_encoded_callback.is_null());
-
   cast_environment_->PostTask(CastEnvironment::VIDEO,
                               FROM_HERE,
                               base::Bind(&EncodeVideoFrameOnEncoderThread,