Add link preload as=document support

third_party/WebKit/Source/platform/network/ResourceRequest.cpp

Index: third_party/WebKit/Source/platform/network/ResourceRequest.cpp
diff --git a/third_party/WebKit/Source/platform/network/ResourceRequest.cpp b/third_party/WebKit/Source/platform/network/ResourceRequest.cpp
index 3e63db337cff78fbb3111d687e3e9e252b3b70dc..9c14caa083fce023250949709418c40789499339 100644
--- a/third_party/WebKit/Source/platform/network/ResourceRequest.cpp
+++ b/third_party/WebKit/Source/platform/network/ResourceRequest.cpp
@@ -77,6 +77,7 @@ ResourceRequest::ResourceRequest(CrossThreadResourceRequestData* data)
     setUseStreamOnResponse(data->m_useStreamOnResponse);
     setSkipServiceWorker(data->m_skipServiceWorker);
     setShouldResetAppCache(data->m_shouldResetAppCache);
+    setLinkPreload(data->m_isLinkPreload);
     setRequestorID(data->m_requestorID);
     setRequestorProcessID(data->m_requestorProcessID);
     setAppCacheHostID(data->m_appCacheHostID);
@@ -123,6 +124,7 @@ std::unique_ptr<CrossThreadResourceRequestData> ResourceRequest::copyData() cons
     data->m_useStreamOnResponse = m_useStreamOnResponse;
     data->m_skipServiceWorker = m_skipServiceWorker;
     data->m_shouldResetAppCache = m_shouldResetAppCache;
+    data->m_isLinkPreload = m_isLinkPreload;
     data->m_requestorID = m_requestorID;
     data->m_requestorProcessID = m_requestorProcessID;
     data->m_appCacheHostID = m_appCacheHostID;
@@ -430,6 +432,7 @@ void ResourceRequest::initialize(const KURL& url)
     m_useStreamOnResponse = false;
     m_skipServiceWorker = WebURLRequest::SkipServiceWorker::None;
     m_shouldResetAppCache = false;
+    m_isLinkPreload = false;
     m_priority = ResourceLoadPriorityLowest;
     m_intraPriorityValue = 0;
     m_requestorID = 0;