'haveImportsLoaded' shouldn't block rendering, if ignoringPendingStylesheets.

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index e70bfb8ccbe5802e68441d2e7333a73d7acbff28..e84d19b00cc9e13e53228bd1232c754cf8251df7 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -5637,6 +5637,11 @@ bool Document::canExecuteScripts(ReasonForCallingCanExecuteScripts reason) {
   return true;
 }
 
+bool Document::isRenderingReady() const {
+  return m_styleEngine->ignoringPendingStylesheets() ||
+         (haveImportsLoaded() && haveRenderBlockingStylesheetsLoaded());
+}
+
 bool Document::allowInlineEventHandler(Node* node,
                                        EventListener* listener,
                                        const String& contextURL,