Implement updateViaCache flag and no-cache by default for main service worker scripts

third_party/WebKit/Source/core/html/HTMLLinkElement.h

Index: third_party/WebKit/Source/core/html/HTMLLinkElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLLinkElement.h b/third_party/WebKit/Source/core/html/HTMLLinkElement.h
index 5c1cf1278dcb3af881b259f9c0a2fde8f115d0d8..fd2c0d5d92e916473c5e84514f7367e18119192e 100644
--- a/third_party/WebKit/Source/core/html/HTMLLinkElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLLinkElement.h
@@ -64,6 +64,7 @@ class CORE_EXPORT HTMLLinkElement final : public HTMLElement,
     return static_cast<DOMTokenList&>(*m_relList);
   }
   String scope() const { return m_scope; }
+  bool useCache() const { return m_useCache; }
 
   const AtomicString& type() const;
 
@@ -161,6 +162,7 @@ class CORE_EXPORT HTMLLinkElement final : public HTMLElement,
   TraceWrapperMember<RelList> m_relList;
   LinkRelAttribute m_relAttribute;
   String m_scope;
+  bool m_useCache;
 
   bool m_createdByParser;
 };