Filter out data urls in the preload scanner

third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp

Index: third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp
diff --git a/third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp b/third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp
index 9c1d3c612f0796af666e3d709e173c53185144b5..5e96c7e57a528a6fcfa7b41189faf15d9f364fc5 100644
--- a/third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp
+++ b/third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.cpp
@@ -238,8 +238,10 @@ void CSSPreloadScanner::emitRule(const SegmentedString& source) {
           PreloadRequest::create(FetchInitiatorTypeNames::css, position, url,
                                  *m_predictedBaseElementURL,
                                  Resource::CSSStyleSheet, m_referrerPolicy);
-      // FIXME: Should this be including the charset in the preload request?
-      m_requests->append(std::move(request));
+      if (request) {
+        // FIXME: Should this be including the charset in the preload request?
+        m_requests->append(std::move(request));
+      }
     }
     m_state = Initial;
   } else if (equalIgnoringCase(m_rule, "charset"))