FrameBuffer::NextFrame now return pair<frame, reason>.

webrtc/modules/video_coding/frame_buffer2_unittest.cc

Index: webrtc/modules/video_coding/frame_buffer2_unittest.cc
diff --git a/webrtc/modules/video_coding/frame_buffer2_unittest.cc b/webrtc/modules/video_coding/frame_buffer2_unittest.cc
index 674ae29bfc9c8945da69224bdadef33e0cc5e7c3..1fdeb71ead1c6e3faa3964fcf1c0da11c57aceb5 100644
--- a/webrtc/modules/video_coding/frame_buffer2_unittest.cc
+++ b/webrtc/modules/video_coding/frame_buffer2_unittest.cc
@@ -135,7 +135,9 @@ class TestFrameBuffer2 : public ::testing::Test {
   void ExtractFrame(int64_t max_wait_time = 0) {
     crit_.Enter();
     if (max_wait_time == 0) {
-      frames_.emplace_back(buffer_.NextFrame(0));
+      auto frame = buffer_.NextFrame(0);
+      if (frame)
+        frames_.emplace_back(std::move(*frame));
       crit_.Leave();
     } else {
       max_wait_time_ = max_wait_time;
@@ -170,7 +172,9 @@ class TestFrameBuffer2 : public ::testing::Test {
         if (tfb->tear_down_)
           return false;
 
-        tfb->frames_.emplace_back(tfb->buffer_.NextFrame(tfb->max_wait_time_));
+        auto frame = tfb->buffer_.NextFrame(tfb->max_wait_time_);
+        if (frame)
+          tfb->frames_.emplace_back(std::move(*frame));
       }
     }
   }