RTC_CHECK crop_width_,crop_height_ are nonnegative

Similar to the two RTC_CHECK_GE's earlier in the
VideoStreamEncoder::ReconfigureEncoder() method (originally added to
webrtc/video/vie_encoder.cc in
https://codereview.webrtc.org/2936393002), add two RTC_CHECK_GE's to
ensure that crop_width_ and crop_height_ are nonnegative.

Bug: b:330482827
Change-Id: Ia4989307b754abb101e50d33beeca4483a694a62
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/346026
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Commit-Queue: Wan-Teh Chang <wtc@google.com>
Cr-Commit-Position: refs/heads/main@{#42017}

video/video_stream_encoder.cc

diff --git a/video/video_stream_encoder.cc b/video/video_stream_encoder.cc
index 2f4c6e9..4390fe3 100644
--- a/video/video_stream_encoder.cc
+++ b/video/video_stream_encoder.cc
@@ -1186,6 +1186,8 @@
       encoder_config_.codec_type == kVideoCodecAV1) {
     // Spatial layers configuration might impose some parity restrictions,
     // thus some cropping might be needed.
+    RTC_CHECK_GE(last_frame_info_->width, codec.width);
+    RTC_CHECK_GE(last_frame_info_->height, codec.height);
     crop_width_ = last_frame_info_->width - codec.width;
     crop_height_ = last_frame_info_->height - codec.height;
     ApplySpatialLayerBitrateLimits(