Delete IsZeroSize method.

webrtc/video/video_quality_test.cc

Index: webrtc/video/video_quality_test.cc
diff --git a/webrtc/video/video_quality_test.cc b/webrtc/video/video_quality_test.cc
index 51160c91c6a2e15b23f8b4c90d536e58eba8478f..5b6ad7373835a16e247fcf21f37775f4b3999707 100644
--- a/webrtc/video/video_quality_test.cc
+++ b/webrtc/video/video_quality_test.cc
@@ -606,12 +606,8 @@ class VideoAnalyzer : public PacketReceiver,
 
   void PerformFrameComparison(const FrameComparison& comparison) {
     // Perform expensive psnr and ssim calculations while not holding lock.
-    double psnr = -1.0;
-    double ssim = -1.0;
-    if (!comparison.reference.IsZeroSize()) {

[stefan-webrtc, 2016/09/05 14:45:25]

I'm pretty sure this was needed when I added this code. Why isn't it now?

-      psnr = I420PSNR(&comparison.reference, &comparison.render);
-      ssim = I420SSIM(&comparison.reference, &comparison.render);
-    }
+    double psnr = I420PSNR(&comparison.reference, &comparison.render);
+    double ssim = I420SSIM(&comparison.reference, &comparison.render);
 
     int64_t input_time_ms = comparison.reference.ntp_time_ms();