Revert of Delete VideoFrame default constructor, and IsZeroSize method.

webrtc/test/frame_generator.cc

 /*
  *  Copyright (c) 2013 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.
  */
 #include "webrtc/test/frame_generator.h"
@@ skipping 170 matching lines @@
 
     double scroll_factor;
     int64_t time_into_frame = ms_since_start % kFrameDisplayTime;
     if (time_into_frame < scroll_time_) {
       scroll_factor = static_cast<double>(time_into_frame) / scroll_time_;
     } else {
       scroll_factor = 1.0;
     }
     CropSourceToScrolledImage(scroll_factor);
 
-    return current_frame_ ? &*current_frame_ : nullptr;
+    return &current_frame_;
   }
 
   void UpdateSourceFrame(size_t frame_num) {
     while (current_frame_num_ != frame_num) {
       current_source_frame_ = file_generator_.NextFrame();
       current_frame_num_ = (current_frame_num_ + 1) % num_frames_;
     }
     RTC_DCHECK(current_source_frame_ != nullptr);
   }
 
@@ skipping 10 matching lines @@
                    pixels_scrolled_x;
     int offset_u = (current_source_frame_->video_frame_buffer()->StrideU() *
                     (pixels_scrolled_y / 2)) +
                    (pixels_scrolled_x / 2);
     int offset_v = (current_source_frame_->video_frame_buffer()->StrideV() *
                     (pixels_scrolled_y / 2)) +
                    (pixels_scrolled_x / 2);
 
     rtc::scoped_refptr<VideoFrameBuffer> frame_buffer(
         current_source_frame_->video_frame_buffer());
-    current_frame_ = rtc::Optional<webrtc::VideoFrame>(webrtc::VideoFrame(
+    current_frame_ = webrtc::VideoFrame(
         new rtc::RefCountedObject<webrtc::WrappedI420Buffer>(
             target_width_, target_height_,
             &frame_buffer->DataY()[offset_y], frame_buffer->StrideY(),
             &frame_buffer->DataU()[offset_u], frame_buffer->StrideU(),
             &frame_buffer->DataV()[offset_v], frame_buffer->StrideV(),
             KeepRefUntilDone(frame_buffer)),
-        kVideoRotation_0, 0));
+        kVideoRotation_0, 0);
   }
 
   Clock* const clock_;
   const int64_t start_time_;
   const int64_t scroll_time_;
   const int64_t pause_time_;
   const size_t num_frames_;
   const int target_width_;
   const int target_height_;
 
   size_t current_frame_num_;
   VideoFrame* current_source_frame_;
-  rtc::Optional<VideoFrame> current_frame_;
+  VideoFrame current_frame_;
   YuvFileGenerator file_generator_;
 };
 
 }  // namespace
 
 FrameForwarder::FrameForwarder() : sink_(nullptr) {}
 
 void FrameForwarder::IncomingCapturedFrame(const VideoFrame& video_frame) {
   rtc::CritScope lock(&crit_);
   if (sink_)
@@ skipping 62 matching lines @@
     files.push_back(file);
   }
 
   return new ScrollingImageFrameGenerator(
       clock, files, source_width, source_height, target_width, target_height,
       scroll_time_ms, pause_time_ms);
 }
 
 }  // namespace test
 }  // namespace webrtc