Delay generation of User-Agent header to URLRequestHttpJob and accept custom User-Agent from XHR/Fe…

third_party/WebKit/Source/core/loader/FrameFetchContext.cpp

Index: third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
index 3e0573ed041b30a2629a12476978a41cab65b7a8..a67676dbb0d5e37b70c3f69b7da89edf9a5690ae 100644
--- a/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameFetchContext.cpp
@@ -180,8 +180,7 @@ LocalFrame* FrameFetchContext::frame() const
 
 void FrameFetchContext::addAdditionalRequestHeaders(ResourceRequest& request, FetchResourceType type)
 {
-    bool isMainResource = type == FetchMainResource;
-    if (!isMainResource) {
+    if (type != FetchMainResource) {
         RefPtr<SecurityOrigin> outgoingOrigin;
         if (!request.didSetHTTPReferrer()) {
             ASSERT(m_document);
@@ -208,7 +207,7 @@ void FrameFetchContext::addAdditionalRequestHeaders(ResourceRequest& request, Fe
     if (frame()->settings() && frame()->settings()->dataSaverEnabled())
         request.setHTTPHeaderField("Save-Data", "on");
 
-    frame()->loader().applyUserAgent(request);
+    request.setDefaultHTTPUserAgent(AtomicString(frame()->loader().userAgent()));
 }
 
 CachePolicy FrameFetchContext::getCachePolicy() const
@@ -322,7 +321,7 @@ void FrameFetchContext::dispatchDidChangeResourcePriority(unsigned long identifi
 
 void FrameFetchContext::prepareRequest(unsigned long identifier, ResourceRequest& request, const ResourceResponse& redirectResponse)
 {
-    frame()->loader().applyUserAgent(request);
+    request.setDefaultHTTPUserAgent(AtomicString(frame()->loader().userAgent()));
     frame()->loader().client()->dispatchWillSendRequest(m_documentLoader, identifier, request, redirectResponse);
 }