https://bugs.webkit.org/show_bug.cgi?id=49227

Reviewed by Dan Bernstein.

* Shared/API/c/WKBase.h:
Add WKDownloadRef.

* UIProcess/API/C/WKAPICast.h:
Add WKDownloadRef <-> DownloadProxy mapping.

* UIProcess/API/C/WKContext.cpp:
(WKContextSetDownloadClient):
Initialize the download client.

* UIProcess/API/C/WKContext.h:
Add new WKContextDownloadClient API.

* UIProcess/API/C/WKDownload.cpp: Added.
* UIProcess/API/C/WKDownload.h:
Add WKDownload files.

* UIProcess/Downloads/DownloadProxy.cpp:
(WebKit::DownloadProxy::didStart):
(WebKit::DownloadProxy::didCreateDestination):
(WebKit::DownloadProxy::didFinish):
Call down to the the WebDownloadClient.

* UIProcess/Downloads/DownloadProxy.messages.in:
Rename DidBegin to DidStart.

* UIProcess/WebContext.cpp:
(WebKit::WebContext::initializeDownloadClient):
Initialize the download client.

* UIProcess/WebContext.h:
(WebKit::WebContext::downloadClient):
Add getter.

* UIProcess/WebDownloadClient.cpp:
(WebKit::WebDownloadClient::didStart):
(WebKit::WebDownloadClient::didCreateDestination):
(WebKit::WebDownloadClient::didFinish):
Call the relevant WKContextDownloadClient functions.

* WebKit2.pro:
* WebKit2.xcodeproj/project.pbxproj:
Add new files.

* WebProcess/Downloads/Download.cpp:
(WebKit::Download::didStart):
* WebProcess/Downloads/Download.h:
* WebProcess/Downloads/mac/DownloadMac.mm:
(-[WKDownloadAsDelegate downloadDidBegin:]):
Rename Download::didBegin to Download::didStart.

* win/WebKit2.vcproj:
Add new files.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@71591 268f45cc-cd09-0410-ab3c-d52691b4dbfc