[Curl] Extract multipart handling from ResourceHandle to CurlRequest.

[Curl] Extract multipart handling from ResourceHandle to CurlRequest.
https://bugs.webkit.org/show_bug.cgi?id=181506

Patch by Basuke Suzuki <Basuke.Suzuki@sony.com> on 2018-01-11
Reviewed by Alex Christensen.

Rename old MultipartHandle class to CurlMultipartHandle and modernize it. Also move the responsibility
of handling multi part from ResourceHandle to CurlRequest. This is required for upcoming NetworkLoadTask.

No new tests because no new behavior.

* platform/Curl.cmake:
* platform/network/curl/CurlMultipartHandle.cpp: Renamed from Source/WebCore/platform/network/curl/MultipartHandle.cpp.
(WebCore::CurlMultipartHandle::createIfNeeded):
(WebCore::CurlMultipartHandle::extractBoundary):
(WebCore::CurlMultipartHandle::extractBoundaryFromContentType):
(WebCore::CurlMultipartHandle::CurlMultipartHandle):
(WebCore::CurlMultipartHandle::didReceiveData):
(WebCore::CurlMultipartHandle::didComplete):
(WebCore::CurlMultipartHandle::processContent):
(WebCore::CurlMultipartHandle::checkForBoundary):
(WebCore::CurlMultipartHandle::matchedLength):
(WebCore::CurlMultipartHandle::parseHeadersIfPossible):
* platform/network/curl/CurlMultipartHandle.h: Renamed from Source/WebCore/platform/network/curl/MultipartHandle.h.
(WebCore::CurlMultipartHandle::~CurlMultipartHandle):
* platform/network/curl/CurlMultipartHandleClient.h: Added.
(WebCore::CurlMultipartHandleClient::~CurlMultipartHandleClient):
* platform/network/curl/CurlRequest.cpp:
(WebCore::CurlRequest::CurlRequest):
(WebCore::CurlRequest::didReceiveHeader):
(WebCore::CurlRequest::didReceiveData):
(WebCore::CurlRequest::didReceiveHeaderFromMultipart):
(WebCore::CurlRequest::didReceiveDataFromMultipart):
(WebCore::CurlRequest::didCompleteTransfer):
(WebCore::CurlRequest::finalizeTransfer):
(WebCore::CurlRequest::invokeDidReceiveResponseForFile):
(WebCore::CurlRequest::invokeDidReceiveResponse):
(WebCore::CurlRequest::completeDidReceiveResponse):
* platform/network/curl/CurlRequest.h:
(WebCore::CurlRequest::create):
* platform/network/curl/ResourceHandleCurlDelegate.cpp:
(WebCore::ResourceHandleCurlDelegate::createCurlRequest):
(WebCore::ResourceHandleCurlDelegate::curlDidReceiveResponse):
(WebCore::ResourceHandleCurlDelegate::curlDidReceiveBuffer):
(WebCore::ResourceHandleCurlDelegate::curlDidComplete):
* platform/network/curl/ResourceHandleCurlDelegate.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@226800 268f45cc-cd09-0410-ab3c-d52691b4dbfc