Set AV1 encoder speed back to 10

The fix for the visual artifacts we observed before with AV1 at speed
10 has been rolled into Chromium so we can bump the encoder speed
back up.

Bug: b:266687023
Change-Id: I9df10b3e420187b7e4bdf74da0bed18fef11deac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4226366
Commit-Queue: Joe Downing <joedow@chromium.org>
Auto-Submit: Joe Downing <joedow@chromium.org>
Reviewed-by: Lambros Lambrou <lambroslambrou@chromium.org>
Commit-Queue: Lambros Lambrou <lambroslambrou@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1102459}

remoting/codec/webrtc_video_encoder_av1.cc

@@ -36,9 +36,9 @@ void DestroyAomCodecContext(aom_codec_ctx_t* codec_ctx) {
 // TODO(joedow): Perform some additional testing to see if this needs tweaking.
 constexpr int kAv1MinimumTargetBitrateKbpsPerMegapixel = 2500;
 
-// A value of 9 provides higher-quality and decent performance based on
-// experimentation.
-constexpr int kAv1DefaultEncoderSpeed = 9;
+// Use the highest possible encoder speed as it produces frames faster than the
+// lower settings, requires fewer CPU resources, and still has low bitrates.
+constexpr int kAv1DefaultEncoderSpeed = 10;
 
 }  // namespace