Teach WebURLRequest about Fetch's "frame type" concept.

Source/platform/network/ResourceRequest.cpp

Index: Source/platform/network/ResourceRequest.cpp
diff --git a/Source/platform/network/ResourceRequest.cpp b/Source/platform/network/ResourceRequest.cpp
index cc956cc58f167ed7f05f7cb34cfcb88067a16aca..07a38ddae6806df1668e70524155cb86bdc16c62 100644
--- a/Source/platform/network/ResourceRequest.cpp
+++ b/Source/platform/network/ResourceRequest.cpp
@@ -54,6 +54,7 @@ PassOwnPtr<ResourceRequest> ResourceRequest::adopt(PassOwnPtr<CrossThreadResourc
     request->setRequestorProcessID(data->m_requestorProcessID);
     request->setAppCacheHostID(data->m_appCacheHostID);
     request->setRequestContext(data->m_requestContext);
+    request->setFrameType(data->m_frameType);
     request->m_referrerPolicy = data->m_referrerPolicy;
     return request.release();
 }
@@ -80,6 +81,7 @@ PassOwnPtr<CrossThreadResourceRequestData> ResourceRequest::copyData() const
     data->m_requestorProcessID = m_requestorProcessID;
     data->m_appCacheHostID = m_appCacheHostID;
     data->m_requestContext = m_requestContext;
+    data->m_frameType = m_frameType;
     data->m_referrerPolicy = m_referrerPolicy;
     return data.release();
 }
@@ -399,6 +401,7 @@ void ResourceRequest::initialize(const KURL& url, ResourceRequestCachePolicy cac
     m_requestorProcessID = 0;
     m_appCacheHostID = 0;
     m_requestContext = blink::WebURLRequest::RequestContextUnspecified;
+    m_frameType = blink::WebURLRequest::FrameTypeNone;
     m_referrerPolicy = ReferrerPolicyDefault;
 }