Get rid of virtual Display::CreateScheduler.

components/mus/surfaces/display_compositor.cc

Index: components/mus/surfaces/display_compositor.cc
diff --git a/components/mus/surfaces/display_compositor.cc b/components/mus/surfaces/display_compositor.cc
index 79e052305c3b3ea96e4c7d4e92bf80c7eda307b5..72ff9437c77d31246874e248dee0e709547aecbb 100644
--- a/components/mus/surfaces/display_compositor.cc
+++ b/components/mus/surfaces/display_compositor.cc
@@ -26,7 +26,10 @@ DisplayCompositor::DisplayCompositor(
     : task_runner_(task_runner),
       surfaces_state_(surfaces_state),
       factory_(surfaces_state->manager(), this),
-      allocator_(surfaces_state->next_id_namespace()) {
+      allocator_(surfaces_state->next_id_namespace()),
+      synthetic_begin_frame_source_(new cc::SyntheticBeginFrameSource(
+          task_runner_.get(),
+          cc::BeginFrameArgs::DefaultInterval())) {
   allocator_.RegisterSurfaceIdNamespace(surfaces_state_->manager());
   surfaces_state_->manager()->RegisterSurfaceFactoryClient(
       allocator_.id_namespace(), this);
@@ -40,25 +43,25 @@ DisplayCompositor::DisplayCompositor(
   if (surfaces_context_provider->ContextCapabilities().surfaceless) {
 #if defined(USE_OZONE)
     display_output_surface = base::WrapUnique(new DirectOutputSurfaceOzone(
-        surfaces_context_provider, widget, task_runner_.get(), GL_TEXTURE_2D,
-        GL_RGB));
+        surfaces_context_provider, widget, synthetic_begin_frame_source_.get(),
+        GL_TEXTURE_2D, GL_RGB));
 #else
     NOTREACHED();
 #endif
   } else {
-    display_output_surface = base::WrapUnique(
-        new DirectOutputSurface(surfaces_context_provider, task_runner_.get()));
+    display_output_surface = base::WrapUnique(new DirectOutputSurface(
+        surfaces_context_provider, synthetic_begin_frame_source_.get()));
   }
 
   int max_frames_pending =
       display_output_surface->capabilities().max_frames_pending;
   DCHECK_GT(max_frames_pending, 0);
 
-  display_.reset(
-      new cc::Display(surfaces_state_->manager(), nullptr /* bitmap_manager */,
-                      nullptr /* gpu_memory_buffer_manager */,
-                      cc::RendererSettings(), allocator_.id_namespace(),
-                      task_runner_.get(), std::move(display_output_surface)));
+  display_.reset(new cc::Display(
+      surfaces_state_->manager(), nullptr /* bitmap_manager */,
+      nullptr /* gpu_memory_buffer_manager */, cc::RendererSettings(),
+      allocator_.id_namespace(), task_runner_.get(),
+      synthetic_begin_frame_source_.get(), std::move(display_output_surface)));
 
   bool init = display_->Initialize(this);
   DCHECK(init);  // The context provider was already bound above.