Set Origin header instead of AccessControlAllowOrigin in ResourceFetcherImpl

I think it's just got mixed up but your cross-checking is appreciated.

Bug: N/A
Change-Id: I88ee161bdadcf732a01082906d87848fd52a90df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1621789Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Commit-Queue: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662034}

content/renderer/fetchers/resource_fetcher_impl.cc

@@ -35,7 +35,6 @@
 namespace {
 
 constexpr int32_t kRoutingId = 0;
-const char kAccessControlAllowOriginHeader[] = "Access-Control-Allow-Origin";
 
 }  // namespace
 
@@ -317,7 +316,7 @@ void ResourceFetcherImpl::Start(
   if (!frame->GetDocument().GetSecurityOrigin().IsNull()) {
     request_.request_initiator =
         static_cast<url::Origin>(frame->GetDocument().GetSecurityOrigin());
-    SetHeader(kAccessControlAllowOriginHeader,
+    SetHeader(net::HttpRequestHeaders::kOrigin,
               blink::WebSecurityOrigin::CreateUnique().ToString().Ascii());
   }
   request_.resource_type =