webview: Disable UseSurfaceLayerForVideo feature.

The UseSurfaceLayerForVideo feature is still enabled in Android WebView
perf tests. WebView isn't compatible with the feature, so force it to
disabled always.

Bug: 853832
Change-Id: Ide874c0947dfad92ea95edfaec9e7c396ea1520d
Reviewed-on: https://chromium-review.googlesource.com/1108385Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568980}

android_webview/lib/aw_main_delegate.cc

@@ -165,6 +165,11 @@ bool AwMainDelegate::BasicStartupComplete(int* exit_code) {
   // WebView does not support AndroidOverlay yet for video overlays.
   CommandLineHelper::AddDisabledFeature(*cl, media::kUseAndroidOverlay.name);
 
+  // WebView doesn't support embedding CompositorFrameSinks which is needed for
+  // UseSurfaceLayerForVideo feature. https://crbug.com/853832
+  CommandLineHelper::AddDisabledFeature(*cl,
+                                        media::kUseSurfaceLayerForVideo.name);
+
   // WebView does not support EME persistent license yet, because it's not
   // clear on how user can remove persistent media licenses from UI.
   CommandLineHelper::AddDisabledFeature(*cl,