[Display Cutout] Do not create DisplayCutoutHostImpl

Do not create DisplayCutoutHostImpl automatically in WebContentsImpl

BUG=859241

Change-Id: I1dff20d653d1712f529f595c3fb9d0ce08eaceeb
Reviewed-on: https://chromium-review.googlesource.com/1129557Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#573451}

content/browser/web_contents/web_contents_impl.cc

@@ -679,7 +679,10 @@ WebContentsImpl::WebContentsImpl(BrowserContext* browser_context)
   host_zoom_map_observer_.reset(new HostZoomMapObserver(this));
 #endif  // !defined(OS_ANDROID)
 
+#if defined(OS_ANDROID)
+  if (base::FeatureList::IsEnabled(features::kDisplayCutoutAPI))
     display_cutout_host_impl_ = std::make_unique<DisplayCutoutHostImpl>(this);
+#endif
 
   registry_.AddInterface(base::BindRepeating(
       &WebContentsImpl::OnColorChooserFactoryRequest, base::Unretained(this)));
@@ -1392,6 +1395,7 @@ const std::string& WebContentsImpl::GetMediaDeviceGroupIDSaltBase() const {
 #if defined(OS_ANDROID)
 
 void WebContentsImpl::SetDisplayCutoutSafeArea(gfx::Insets insets) {
+  if (display_cutout_host_impl_)
     display_cutout_host_impl_->SetDisplayCutoutSafeArea(insets);
 }
 
@@ -4152,9 +4156,11 @@ void WebContentsImpl::ReadyToCommitNavigation(
   SetNotWaitingForResponse();
 
   // Reset the viewport fit
+  if (display_cutout_host_impl_) {
     display_cutout_host_impl_->ViewportFitChangedForFrame(
         navigation_handle->GetRenderFrameHost(),
         blink::mojom::ViewportFit::kAuto);
+  }
 }
 
 void WebContentsImpl::DidFinishNavigation(NavigationHandle* navigation_handle) {