Defer ChromeClient::attachRootGraphicsLayer until after compositing update.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 7e31817abf33c8d1de944ee18ec1f3c55a90ce2c..05ff38f2f8776437445527b12297ff3c72907a88 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -3735,7 +3735,13 @@ void WebViewImpl::setPageOverlayColor(WebColor color) {
 
   m_pageColorOverlay = PageOverlay::create(
       mainFrameImpl(), WTF::makeUnique<ColorOverlay>(color));
-  m_pageColorOverlay->update();
+
+  // Run compositing update before calling updatePageOverlays.
+  mainFrameImpl()
+      ->frameView()
+      ->updateLifecycleToCompositingCleanPlusScrolling();
+
+  updatePageOverlays();
 }
 
 WebPageImportanceSignals* WebViewImpl::pageImportanceSignals() {