Remove an unused variable.

Bug: 775328
Change-Id: I96c860f729c58d3dff9893255978f72eb2bb448b
Reviewed-on: https://chromium-review.googlesource.com/727039
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509917}

media/base/mac/video_frame_mac_unittests.cc

@@ -114,7 +114,6 @@ TEST(VideoFrameMac, CheckWrapperFrame) {
       {PIXEL_FORMAT_NV12, kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange},
   };
 
-  const gfx::Size size(kWidth, kHeight);
   for (const auto& format_pair : format_pairs) {
     base::ScopedCFTypeRef<CVPixelBufferRef> pb;
     CVPixelBufferCreate(nullptr, kWidth, kHeight, format_pair.corevideo,