Remove the --disable-begin-frame-scheduling flag

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 67dffecb4b58214be648392d729d34f52f41ab48..672e2033a84638cd7985f0d34ccd19e01ef5ccf0 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -475,8 +475,7 @@ cc::LayerTreeSettings RenderWidgetCompositor::GenerateLayerTreeSettings(
     settings.create_low_res_tiling = true;
   if (cmd.HasSwitch(switches::kDisableLowResTiling))
     settings.create_low_res_tiling = false;
-  if (!cmd.HasSwitch(cc::switches::kDisableBeginFrameScheduling))
-    settings.use_external_begin_frame_source = true;
+  settings.use_external_begin_frame_source = true;
 
   if (cmd.HasSwitch(switches::kEnableRGBA4444Textures) &&
       !cmd.HasSwitch(switches::kDisableRGBA4444Textures)) {