Allow switching DirectCompositionSurfaceWin between drawing modes.

cc/output/software_renderer.cc

Index: cc/output/software_renderer.cc
diff --git a/cc/output/software_renderer.cc b/cc/output/software_renderer.cc
index c39672c3855a718ef9ea640664420afda46210f0..8bd1e38195e2aca400fe994fab7a757886209bf2 100644
--- a/cc/output/software_renderer.cc
+++ b/cc/output/software_renderer.cc
@@ -583,6 +583,10 @@ void SoftwareRenderer::CopyCurrentRenderPassToBitmap(
   request->SendBitmapResult(std::move(bitmap));
 }
 
+void SoftwareRenderer::SetEnableDCLayers(bool enable) {
+  NOTIMPLEMENTED();
+}
+
 void SoftwareRenderer::DidChangeVisibility() {
   if (visible_)
     output_surface_->EnsureBackbuffer();