Switch to CPUUSED=5 for VP9.

VP9's CPUUSED settings go to 6, but 5 appears to provide the best
balance of quality vs performance right now.

BUG=260879

Review URL: https://codereview.chromium.org/354943003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@280498 0039d316-1c4b-4281-b951-d872f2087c98

remoting/codec/video_encoder_vpx.cc

@@ -133,10 +133,9 @@ ScopedVpxCodec CreateVP9Codec(const webrtc::DesktopSize& size,
   if (vpx_codec_enc_init(codec.get(), algo, &config, 0))
     return ScopedVpxCodec();
 
-  // VP9 encode doesn't yet support Realtime, so falls back to Good quality,
-  // for which 4 is the lowest CPU usage.
+  // Request the lowest-CPU encode feature-set that VP9 supports.
   // Note that this is configured via the same parameter as for VP8.
-  if (vpx_codec_control(codec.get(), VP8E_SET_CPUUSED, 4))
+  if (vpx_codec_control(codec.get(), VP8E_SET_CPUUSED, 5))
     return ScopedVpxCodec();
 
   // Use the lowest level of noise sensitivity so as to spend less time