Revert of Delete VideoFrame default constructor, and IsZeroSize method.

webrtc/modules/video_coding/generic_encoder.cc

 /*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
 
@@ skipping 105 matching lines @@
 }
 
 int32_t VCMGenericEncoder::SetPeriodicKeyFrames(bool enable) {
   RTC_DCHECK_RUNS_SERIALIZED(&race_checker_);
   return encoder_->SetPeriodicKeyFrames(enable);
 }
 
 int32_t VCMGenericEncoder::RequestFrame(
     const std::vector<FrameType>& frame_types) {
   RTC_DCHECK_RUNS_SERIALIZED(&race_checker_);
-
-  // TODO(nisse): Used only with internal source. Delete as soon as
-  // that feature is removed. The only implementation I've been able
-  // to find ignores what's in the frame.
-  return encoder_->Encode(VideoFrame(I420Buffer::Create(1, 1),
-                                     kVideoRotation_0, 0),
-                          NULL, &frame_types);
-  return 0;
+  VideoFrame image;
+  return encoder_->Encode(image, NULL, &frame_types);
 }
 
 bool VCMGenericEncoder::InternalSource() const {
   return internal_source_;
 }
 
 bool VCMGenericEncoder::SupportsNativeHandle() const {
   RTC_DCHECK_RUNS_SERIALIZED(&race_checker_);
   return encoder_->SupportsNativeHandle();
 }
@@ skipping 22 matching lines @@
     media_opt_->UpdateWithEncodedData(encoded_image);
     if (internal_source_) {
       // Signal to encoder to drop next frame.
       result.drop_next_frame = media_opt_->DropFrame();
     }
   }
   return result;
 }
 
 }  // namespace webrtc