From e5e5292adb97c9dcbf45bfc85d030b0eeb25d5fd Mon Sep 17 00:00:00 2001
From: nisse <nisse@webrtc.org>
Date: Wed, 25 May 2016 06:25:17 -0700
Subject: [PATCH] Let VideoRenderFrames::FrameToRender return a rtc::Optional.

This eliminates one use of IsZeroSize.

BUG=webrtc:5682

Review-Url: https://codereview.webrtc.org/2008513003
Cr-Commit-Position: refs/heads/master@{#12891}
---
 webrtc/common_video/incoming_video_stream.cc | 9 +++------
 webrtc/common_video/video_render_frames.cc   | 6 +++---
 webrtc/common_video/video_render_frames.h    | 5 +++--
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/webrtc/common_video/incoming_video_stream.cc b/webrtc/common_video/incoming_video_stream.cc
index 5fc8eae0bd..7bc24861b8 100644
--- a/webrtc/common_video/incoming_video_stream.cc
+++ b/webrtc/common_video/incoming_video_stream.cc
@@ -175,7 +175,7 @@ bool IncomingVideoStream::IncomingVideoStreamProcess() {
     }
 
     // Get a new frame to render and the time for the frame after this one.
-    VideoFrame frame_to_render;
+    rtc::Optional<VideoFrame> frame_to_render;
     uint32_t wait_time;
     {
       rtc::CritScope cs(&buffer_critsect_);
@@ -189,17 +189,14 @@ bool IncomingVideoStream::IncomingVideoStreamProcess() {
     }
     deliver_buffer_event_->StartTimer(false, wait_time);
 
-    DeliverFrame(frame_to_render);
+    if (frame_to_render)
+      DeliverFrame(*frame_to_render);
   }
   return true;
 }
 
 void IncomingVideoStream::DeliverFrame(const VideoFrame& video_frame) {
   rtc::CritScope cs(&thread_critsect_);
-  if (video_frame.IsZeroSize()) {
-    // No frame.
-    return;
-  }
 
   // Send frame for rendering.
   if (external_callback_) {
diff --git a/webrtc/common_video/video_render_frames.cc b/webrtc/common_video/video_render_frames.cc
index 3e5dfe9d10..62b317d966 100644
--- a/webrtc/common_video/video_render_frames.cc
+++ b/webrtc/common_video/video_render_frames.cc
@@ -53,11 +53,11 @@ int32_t VideoRenderFrames::AddFrame(const VideoFrame& new_frame) {
   return static_cast<int32_t>(incoming_frames_.size());
 }
 
-VideoFrame VideoRenderFrames::FrameToRender() {
-  VideoFrame render_frame;
+rtc::Optional<VideoFrame> VideoRenderFrames::FrameToRender() {
+  rtc::Optional<VideoFrame> render_frame;
   // Get the newest frame that can be released for rendering.
   while (!incoming_frames_.empty() && TimeToNextFrameRelease() <= 0) {
-    render_frame = incoming_frames_.front();
+    render_frame = rtc::Optional<VideoFrame>(incoming_frames_.front());
     incoming_frames_.pop_front();
   }
   return render_frame;
diff --git a/webrtc/common_video/video_render_frames.h b/webrtc/common_video/video_render_frames.h
index 450c1f2215..acd955887f 100644
--- a/webrtc/common_video/video_render_frames.h
+++ b/webrtc/common_video/video_render_frames.h
@@ -15,6 +15,7 @@
 
 #include <list>
 
+#include "webrtc/base/optional.h"
 #include "webrtc/video_frame.h"
 
 namespace webrtc {
@@ -27,8 +28,8 @@ class VideoRenderFrames {
   // Add a frame to the render queue
   int32_t AddFrame(const VideoFrame& new_frame);
 
-  // Get a frame for rendering, or a zero-size frame if it's not time to render.
-  VideoFrame FrameToRender();
+  // Get a frame for rendering, or false if it's not time to render.
+  rtc::Optional<VideoFrame> FrameToRender();
 
   // Releases all frames
   int32_t ReleaseAllFrames();