Replace VideoEncoderFactory::QueryVideoEncoder with VideoEncoder::GetEncoderInfo

Make implementation of VideoEncoderFactory::QueryVideoEncoder optional
until it is removed downstream and remove all implementations of it.

Bug: webrtc:10065
Change-Id: Ibb1f9612234e536651ce53f05ee048a5d172a41f
Reviewed-on: https://webrtc-review.googlesource.com/c/113065
Commit-Queue: Mirta Dvornicic <mirtad@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25924}
diff --git a/api/video_codecs/video_encoder_factory.h b/api/video_codecs/video_encoder_factory.h
index 7958d16..7b2b156 100644
--- a/api/video_codecs/video_encoder_factory.h
+++ b/api/video_codecs/video_encoder_factory.h
@@ -25,6 +25,9 @@
  public:
   // TODO(magjed): Try to get rid of this struct.
   struct CodecInfo {
+    CodecInfo();
+    ~CodecInfo();
+
     // |is_hardware_accelerated| is true if the encoders created by this factory
     // of the given codec will use hardware support.
     bool is_hardware_accelerated;
@@ -43,7 +46,7 @@
   // Returns information about how this format will be encoded. The specified
   // format must be one of the supported formats by this factory.
   // TODO(magjed): Try to get rid of this method.
-  virtual CodecInfo QueryVideoEncoder(const SdpVideoFormat& format) const = 0;
+  virtual CodecInfo QueryVideoEncoder(const SdpVideoFormat& format) const;
 
   // Creates a VideoEncoder for the specified format.
   virtual std::unique_ptr<VideoEncoder> CreateVideoEncoder(