Patch on top of https://codereview.chromium.org/433793002/

Source/modules/serviceworkers/Request.cpp

Index: Source/modules/serviceworkers/Request.cpp
diff --git a/Source/modules/serviceworkers/Request.cpp b/Source/modules/serviceworkers/Request.cpp
index d8bcbf5fa35bb522709e850629602b72a06f74d4..a7a17e687e6e20c1e93aef42c5238c3d16617973 100644
--- a/Source/modules/serviceworkers/Request.cpp
+++ b/Source/modules/serviceworkers/Request.cpp
@@ -187,12 +187,12 @@ Request* Request::create(ExecutionContext* context, const String& input, const D
     return createRequestWithRequestData(request, RequestInit(context, init, exceptionState), FetchRequestData::CORSMode, FetchRequestData::OmitCredentials, exceptionState);
 }
 
-Request* Request::create(ExecutionContext* context, Request* input, ExceptionState& exceptionState)
+Request* Request::create(ExecutionContext* context, const Request* input, ExceptionState& exceptionState)
 {
     return create(context, input, Dictionary(), exceptionState);
 }
 
-Request* Request::create(ExecutionContext* context, Request* input, const Dictionary& init, ExceptionState& exceptionState)
+Request* Request::create(ExecutionContext* context, const Request* input, const Dictionary& init, ExceptionState& exceptionState)
 {
     // "1. Let |request| be |input|'s associated request, if |input| is a
     // Request object, and a new request otherwise."
@@ -301,7 +301,7 @@ String Request::credentials() const
     return "";
 }
 
-void Request::populateWebServiceWorkerRequest(WebServiceWorkerRequest& webRequest)
+void Request::populateWebServiceWorkerRequest(WebServiceWorkerRequest& webRequest) const
 {
     webRequest.setMethod(method());
     webRequest.setURL(m_request->url());