Progress towards implementing downloads with NetworkSession

Progress towards implementing downloads with NetworkSession
https://bugs.webkit.org/show_bug.cgi?id=152371

Reviewed by Darin Adler.

* NetworkProcess/NetworkProcess.cpp:
(WebKit::NetworkProcess::downloadRequest):
(WebKit::NetworkProcess::resumeDownload):
(WebKit::NetworkProcess::cancelDownload):
* NetworkProcess/NetworkProcess.h:
* NetworkProcess/NetworkProcess.messages.in:
* Shared/Authentication/AuthenticationManager.cpp:
(WebKit::AuthenticationManager::didReceiveAuthenticationChallenge):
* Shared/Authentication/AuthenticationManager.h:
* Shared/Downloads/Download.cpp:
(WebKit::Download::Download):
(WebKit::Download::didReceiveAuthenticationChallenge):
* Shared/Downloads/Download.h:
* Shared/Downloads/DownloadManager.cpp:
(WebKit::DownloadManager::startDownload):
(WebKit::DownloadManager::convertHandleToDownload):
(WebKit::DownloadManager::resumeDownload):
(WebKit::DownloadManager::cancelDownload):
(WebKit::DownloadManager::downloadFinished):
(WebKit::DownloadManager::didCreateDownload):
* Shared/Downloads/DownloadManager.h:
* Shared/Downloads/cocoa: Added.
* Shared/Downloads/cocoa/DownloadCocoa.mm: Added.
(WebKit::Download::start):
(WebKit::Download::resume):
(WebKit::Download::cancel):
(WebKit::Download::platformInvalidate):
* Shared/Downloads/ios/DownloadIOS.mm:
* Shared/Downloads/mac/DownloadMac.mm:
(WebKit::Download::start):
(WebKit::Download::startWithHandle):
(WebKit::Download::resume):
* UIProcess/WebProcessPool.cpp:
(WebKit::WebProcessPool::resumeDownload):
* UIProcess/WebProcessPool.h:
* WebKit2.xcodeproj/project.pbxproj:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@194211 268f45cc-cd09-0410-ab3c-d52691b4dbfc