VideoFrameBuffer: Make non-const data access explicit

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc

Index: webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc
diff --git a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc
index e905fd0199c612c58d3787023c1e53528503ce76..c80ccbb73a553540bde2c3b4edbde902a8486c6a 100644
--- a/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc
+++ b/webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_decoder.cc
@@ -64,9 +64,9 @@ rtc::scoped_refptr<webrtc::VideoFrameBuffer> VideoFrameBufferForPixelBuffer(
   int src_uv_stride = CVPixelBufferGetBytesPerRowOfPlane(pixel_buffer, 1);
   int ret = libyuv::NV12ToI420(
       src_y, src_y_stride, src_uv, src_uv_stride,
-      buffer->data(webrtc::kYPlane), buffer->stride(webrtc::kYPlane),
-      buffer->data(webrtc::kUPlane), buffer->stride(webrtc::kUPlane),
-      buffer->data(webrtc::kVPlane), buffer->stride(webrtc::kVPlane),
+      buffer->MutableData(webrtc::kYPlane), buffer->stride(webrtc::kYPlane),
+      buffer->MutableData(webrtc::kUPlane), buffer->stride(webrtc::kUPlane),
+      buffer->MutableData(webrtc::kVPlane), buffer->stride(webrtc::kVPlane),
       width, height);
   CVPixelBufferUnlockBaseAddress(pixel_buffer, kCVPixelBufferLock_ReadOnly);
   if (ret) {