The download client should be able to determine if a placeholder shou…

…ld be used

https://bugs.webkit.org/show_bug.cgi?id=278737
rdar://134794671

Reviewed by Alex Christensen.

The download client should be able to determine if a placeholder should be used for the final location of the
download. This patch prepares for this by passing the value from the UI process to the Networking process.

This was previously landed in <https://commits.webkit.org/283043@main>. This version addresses a build error.

* Source/WebKit/NetworkProcess/Downloads/Download.h:
* Source/WebKit/NetworkProcess/Downloads/DownloadManager.cpp:
(WebKit::DownloadManager::publishDownloadProgress):
* Source/WebKit/NetworkProcess/Downloads/DownloadManager.h:
* Source/WebKit/NetworkProcess/Downloads/PendingDownload.cpp:
(WebKit::PendingDownload::publishProgress):
(WebKit::PendingDownload::didBecomeDownload):
* Source/WebKit/NetworkProcess/Downloads/PendingDownload.h:
* Source/WebKit/NetworkProcess/Downloads/cocoa/DownloadCocoa.mm:
(WebKit::Download::publishProgress):
* Source/WebKit/NetworkProcess/NetworkProcess.cpp:
(WebKit::NetworkProcess::publishDownloadProgress):
* Source/WebKit/NetworkProcess/NetworkProcess.h:
* Source/WebKit/NetworkProcess/NetworkProcess.messages.in:
* Source/WebKit/Shared/API/Cocoa/WebKitPrivate.h:
* Source/WebKit/UIProcess/API/Cocoa/_WKDownload.mm:
(-[_WKDownload publishProgressAtURL:]):
* Source/WebKit/UIProcess/API/Cocoa/WKDownload.mm:
(-[WKDownload setDelegate:]):
* Source/WebKit/UIProcess/API/Cocoa/WKDownloadDelegate.h:
* Source/WebKit/UIProcess/API/Cocoa/WKDownloadDelegatePrivate.h: Added.
* Source/WebKit/UIProcess/Downloads/DownloadProxy.cpp:
(WebKit::DownloadProxy::decideDestinationWithSuggestedFilename):
* Source/WebKit/UIProcess/Downloads/DownloadProxy.h:
(WebKit::DownloadProxy::setUseDownloadPlaceholder):
* Source/WebKit/UIProcess/Downloads/DownloadProxyCocoa.mm:
(WebKit::DownloadProxy::publishProgress):
* Source/WebKit/WebKit.xcodeproj/project.pbxproj:
* Tools/TestWebKitAPI/Tests/WebKitCocoa/Download.mm:
(TestWebKitAPI::DecidePlaceholderPolicy)):
* Tools/TestWebKitAPI/cocoa/TestDownloadDelegate.h:
* Tools/TestWebKitAPI/cocoa/TestDownloadDelegate.mm:
(-[TestDownloadDelegate _download:decidePlaceholderPolicy:]):

Canonical link: https://commits.webkit.org/283071@main

Source/WebKit/NetworkProcess/Downloads/Download.h

@@ -31,6 +31,7 @@
 #include "MessageSender.h"
 #include "NetworkDataTask.h"
 #include "SandboxExtension.h"
+#include "UseDownloadPlaceholder.h"
 #include <WebCore/AuthenticationChallenge.h>
 #include <WebCore/ResourceRequest.h>
 #include <memory>
@@ -90,7 +91,7 @@ class Download : public IPC::MessageSender, public CanMakeWeakPtr<Download>, pub
 #endif
 
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-    void publishProgress(const URL&, std::span<const uint8_t>);
+    void publishProgress(const URL&, std::span<const uint8_t>, WebKit::UseDownloadPlaceholder);
 #endif
 
     DownloadID downloadID() const { return m_downloadID; }

Source/WebKit/NetworkProcess/Downloads/DownloadManager.cpp

@@ -129,12 +129,12 @@ void DownloadManager::cancelDownload(DownloadID downloadID, CompletionHandler<vo
 
 #if PLATFORM(COCOA)
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-void DownloadManager::publishDownloadProgress(DownloadID downloadID, const URL& url, std::span<const uint8_t> bookmarkData)
+void DownloadManager::publishDownloadProgress(DownloadID downloadID, const URL& url, std::span<const uint8_t> bookmarkData, WebKit::UseDownloadPlaceholder useDownloadPlaceholder)
 {
     if (auto* download = m_downloads.get(downloadID))
-        download->publishProgress(url, bookmarkData);
+        download->publishProgress(url, bookmarkData, useDownloadPlaceholder);
     else if (auto* pendingDownload = m_pendingDownloads.get(downloadID))
-        pendingDownload->publishProgress(url, bookmarkData);
+        pendingDownload->publishProgress(url, bookmarkData, useDownloadPlaceholder);
 }
 #else
 void DownloadManager::publishDownloadProgress(DownloadID downloadID, const URL& url, SandboxExtension::Handle&& sandboxExtensionHandle)

Source/WebKit/NetworkProcess/Downloads/DownloadManager.h

@@ -31,6 +31,7 @@
 #include "PendingDownload.h"
 #include "PolicyDecision.h"
 #include "SandboxExtension.h"
+#include "UseDownloadPlaceholder.h"
 #include <WebCore/NotImplemented.h>
 #include <wtf/CheckedRef.h>
 #include <wtf/Forward.h>
@@ -101,7 +102,7 @@ class DownloadManager : public CanMakeCheckedPtr<DownloadManager> {
     void cancelDownload(DownloadID, CompletionHandler<void(std::span<const uint8_t>)>&&);
 #if PLATFORM(COCOA)
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-    void publishDownloadProgress(DownloadID, const URL&, std::span<const uint8_t> bookmarkData);
+    void publishDownloadProgress(DownloadID, const URL&, std::span<const uint8_t> bookmarkData, WebKit::UseDownloadPlaceholder);
 #else
     void publishDownloadProgress(DownloadID, const URL&, SandboxExtension::Handle&&);
 #endif

Source/WebKit/NetworkProcess/Downloads/PendingDownload.cpp

@@ -81,11 +81,12 @@ void PendingDownload::cancel(CompletionHandler<void(std::span<const uint8_t>)>&&
 
 #if PLATFORM(COCOA)
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-void PendingDownload::publishProgress(const URL& url, std::span<const uint8_t> bookmarkData)
+void PendingDownload::publishProgress(const URL& url, std::span<const uint8_t> bookmarkData, UseDownloadPlaceholder useDownloadPlaceholder)
 {
     ASSERT(!m_progressURL.isValid());
     m_progressURL = url;
     m_bookmarkData = bookmarkData;
+    m_useDownloadPlaceholder = useDownloadPlaceholder;
 }
 #else
 void PendingDownload::publishProgress(const URL& url, SandboxExtension::Handle&& sandboxExtension)
@@ -101,7 +102,7 @@ void PendingDownload::didBecomeDownload(const std::unique_ptr<Download>& downloa
     if (!m_progressURL.isValid())
         return;
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-    download->publishProgress(m_progressURL, m_bookmarkData);
+    download->publishProgress(m_progressURL, m_bookmarkData, m_useDownloadPlaceholder);
 #else
     download->publishProgress(m_progressURL, WTFMove(m_progressSandboxExtension));
 #endif

Source/WebKit/NetworkProcess/Downloads/PendingDownload.h

@@ -29,6 +29,7 @@
 #include "MessageSender.h"
 #include "NetworkLoadClient.h"
 #include "SandboxExtension.h"
+#include "UseDownloadPlaceholder.h"
 #include <wtf/TZoneMalloc.h>
 
 namespace WebKit {
@@ -66,7 +67,7 @@ class PendingDownload : public NetworkLoadClient, public IPC::MessageSender, pub
 
 #if PLATFORM(COCOA)
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-    void publishProgress(const URL&, std::span<const uint8_t>);
+    void publishProgress(const URL&, std::span<const uint8_t>, UseDownloadPlaceholder);
 #else
     void publishProgress(const URL&, SandboxExtension::Handle&&);
 #endif
@@ -97,6 +98,7 @@ class PendingDownload : public NetworkLoadClient, public IPC::MessageSender, pub
     URL m_progressURL;
 #if HAVE(MODERN_DOWNLOADPROGRESS)
     Vector<uint8_t> m_bookmarkData;
+    UseDownloadPlaceholder m_useDownloadPlaceholder { UseDownloadPlaceholder::No };
 #else
     SandboxExtension::Handle m_progressSandboxExtension;
 #endif

Source/WebKit/NetworkProcess/Downloads/cocoa/DownloadCocoa.mm

@@ -90,7 +90,7 @@
 }
 
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-void Download::publishProgress(const URL& url, std::span<const uint8_t> bookmarkData)
+void Download::publishProgress(const URL& url, std::span<const uint8_t> bookmarkData, UseDownloadPlaceholder useDownloadPlaceholder)
 {
     if (m_progress) {
         RELEASE_LOG(Network, "Progress is already being published for download.");
@@ -110,7 +110,8 @@
     bool shouldEnableModernDownloadProgress = CFPreferencesGetAppBooleanValue(CFSTR("EnableModernDownloadProgress"), CFSTR("com.apple.WebKit"), NULL);
 
     if (shouldEnableModernDownloadProgress) {
-        m_progress = adoptNS([[WKModernDownloadProgress alloc] initWithDownloadTask:m_downloadTask.get() download:*this URL:(NSURL *)url]);
+        NSData *accessToken = [NSData data]; // FIXME: replace with actual access token
+        m_progress = adoptNS([[WKModernDownloadProgress alloc] initWithDownloadTask:m_downloadTask.get() download:*this URL:(NSURL *)url useDownloadPlaceholder:useDownloadPlaceholder == WebKit::UseDownloadPlaceholder::Yes liveActivityAccessToken:accessToken]);
         [m_progress publish];
     } else {
         m_progress = adoptNS([[WKDownloadProgress alloc] initWithDownloadTask:m_downloadTask.get() download:*this URL:(NSURL *)url sandboxExtension:nullptr]);

Source/WebKit/NetworkProcess/NetworkProcess.cpp

@@ -2141,9 +2141,9 @@ void NetworkProcess::cancelDownload(DownloadID downloadID, CompletionHandler<voi
 
 #if PLATFORM(COCOA)
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-void NetworkProcess::publishDownloadProgress(DownloadID downloadID, const URL& url, std::span<const uint8_t> bookmarkData)
+void NetworkProcess::publishDownloadProgress(DownloadID downloadID, const URL& url, std::span<const uint8_t> bookmarkData, WebKit::UseDownloadPlaceholder useDownloadPlaceholder)
 {
-    downloadManager().publishDownloadProgress(downloadID, url, bookmarkData);
+    downloadManager().publishDownloadProgress(downloadID, url, bookmarkData, useDownloadPlaceholder);
 }
 #else
 void NetworkProcess::publishDownloadProgress(DownloadID downloadID, const URL& url, SandboxExtension::Handle&& sandboxExtensionHandle)
@@ -2157,7 +2157,7 @@ void NetworkProcess::findPendingDownloadLocation(NetworkDataTask& networkDataTas
 {
     String suggestedFilename = networkDataTask.suggestedFilename();
 
-    downloadProxyConnection()->sendWithAsyncReply(Messages::DownloadProxy::DecideDestinationWithSuggestedFilename(response, suggestedFilename), [this, protectedThis = Ref { *this }, completionHandler = WTFMove(completionHandler), networkDataTask = Ref { networkDataTask }] (String&& destination, SandboxExtension::Handle&& sandboxExtensionHandle, AllowOverwrite allowOverwrite) mutable {
+    downloadProxyConnection()->sendWithAsyncReply(Messages::DownloadProxy::DecideDestinationWithSuggestedFilename(response, suggestedFilename), [this, protectedThis = Ref { *this }, completionHandler = WTFMove(completionHandler), networkDataTask = Ref { networkDataTask }] (String&& destination, SandboxExtension::Handle&& sandboxExtensionHandle, AllowOverwrite allowOverwrite, WebKit::UseDownloadPlaceholder usePlaceholder) mutable {
         auto downloadID = *networkDataTask->pendingDownloadID();
         if (destination.isEmpty())
             return completionHandler(PolicyAction::Ignore);
@@ -2166,6 +2166,14 @@ void NetworkProcess::findPendingDownloadLocation(NetworkDataTask& networkDataTas
         if (networkDataTask->state() == NetworkDataTask::State::Canceling || networkDataTask->state() == NetworkDataTask::State::Completed)
             return;
 
+#if HAVE(MODERN_DOWNLOADPROGRESS)
+        bool shouldEnableModernDownloadProgress = CFPreferencesGetAppBooleanValue(CFSTR("EnableModernDownloadProgress"), CFSTR("com.apple.WebKit"), nullptr);
+        if (shouldEnableModernDownloadProgress)
+            publishDownloadProgress(downloadID, URL::fileURLWithFileSystemPath(destination), std::span<const uint8_t>(), usePlaceholder);
+#else
+        UNUSED_PARAM(usePlaceholder);
+#endif
+
         if (downloadManager().download(downloadID)) {
             // The completion handler already called dataTaskBecameDownloadTask().
             return;

Source/WebKit/NetworkProcess/NetworkProcess.h

@@ -33,6 +33,7 @@
 #include "DownloadManager.h"
 #include "NetworkContentRuleListManager.h"
 #include "QuotaIncreaseRequestIdentifier.h"
+#include "UseDownloadPlaceholder.h"
 #include "WebPageProxyIdentifier.h"
 #include "WebResourceLoadStatisticsStore.h"
 #include "WebsiteData.h"
@@ -483,7 +484,7 @@ class NetworkProcess final : public AuxiliaryProcess, private DownloadManager::C
     void cancelDownload(DownloadID, CompletionHandler<void(std::span<const uint8_t>)>&&);
 #if PLATFORM(COCOA)
 #if HAVE(MODERN_DOWNLOADPROGRESS)
-    void publishDownloadProgress(DownloadID, const URL&, std::span<const uint8_t> bookmarkData);
+    void publishDownloadProgress(DownloadID, const URL&, std::span<const uint8_t> bookmarkData, WebKit::UseDownloadPlaceholder);
 #else
     void publishDownloadProgress(DownloadID, const URL&, SandboxExtensionHandle&&);
 #endif

Source/WebKit/NetworkProcess/NetworkProcess.messages.in

@@ -52,9 +52,6 @@ messages -> NetworkProcess LegacyReceiver {
     DownloadRequest(PAL::SessionID sessionID, WebKit::DownloadID downloadID, WebCore::ResourceRequest request, std::optional<WebCore::SecurityOriginData> topOrigin, std::optional<WebKit::NavigatingToAppBoundDomain> isNavigatingToAppBoundDomain, String suggestedFilename)
     ResumeDownload(PAL::SessionID sessionID, WebKit::DownloadID downloadID, std::span<const uint8_t> resumeData, String path, WebKit::SandboxExtensionHandle sandboxExtensionHandle, enum:bool WebKit::CallDownloadDidStart callDownloadDidStart)
     CancelDownload(WebKit::DownloadID downloadID) -> (std::span<const uint8_t> resumeData)
-#if HAVE(MODERN_DOWNLOADPROGRESS)
-    PublishDownloadProgress(WebKit::DownloadID downloadID, URL url, std::span<const uint8_t> bookmarkData)
-#endif
 #if PLATFORM(COCOA) && !HAVE(MODERN_DOWNLOADPROGRESS)
     PublishDownloadProgress(WebKit::DownloadID downloadID, URL url, WebKit::SandboxExtensionHandle sandboxExtensionHandle)
 #endif

Source/WebKit/Shared/API/Cocoa/WebKitPrivate.h

@@ -23,6 +23,7 @@
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#import <WebKit/WKDownloadDelegatePrivate.h>
 #import <WebKit/WKHistoryDelegatePrivate.h>
 #import <WebKit/WKNavigationPrivate.h>
 #import <WebKit/WKProcessPoolPrivate.h>

Source/WebKit/UIProcess/API/APIDownloadClient.h

@@ -29,6 +29,7 @@
 #include "AuthenticationChallengeProxy.h"
 #include "AuthenticationDecisionListener.h"
 #include "DownloadID.h"
+#include "DownloadProxy.h"
 #include <wtf/CompletionHandler.h>
 #include <wtf/TZoneMallocInlines.h>
 #include <wtf/text/WTFString.h>
@@ -41,7 +42,6 @@ class ResourceResponse;
 
 namespace WebKit {
 class AuthenticationChallengeProxy;
-class DownloadProxy;
 class WebsiteDataStore;
 class WebProtectionSpace;
 
@@ -60,6 +60,9 @@ class DownloadClient : public RefCounted<DownloadClient> {
     virtual void legacyDidStart(WebKit::DownloadProxy&) { }
     virtual void didReceiveAuthenticationChallenge(WebKit::DownloadProxy&, WebKit::AuthenticationChallengeProxy& challenge) { challenge.listener().completeChallenge(WebKit::AuthenticationChallengeDisposition::Cancel); }
     virtual void didReceiveData(WebKit::DownloadProxy&, uint64_t, uint64_t, uint64_t) { }
+#if HAVE(MODERN_DOWNLOADPROGRESS)
+    virtual void decidePlaceholderPolicy(WebKit::DownloadProxy&, CompletionHandler<void(WebKit::UseDownloadPlaceholder)>&& completionHandler) { completionHandler(WebKit::UseDownloadPlaceholder::No); }
+#endif
     virtual void decideDestinationWithSuggestedFilename(WebKit::DownloadProxy&, const WebCore::ResourceResponse&, const WTF::String&, CompletionHandler<void(WebKit::AllowOverwrite, WTF::String)>&& completionHandler) { completionHandler(WebKit::AllowOverwrite::No, { }); }
     virtual void didCreateDestination(WebKit::DownloadProxy&, const WTF::String&) { }
     virtual void didFinish(WebKit::DownloadProxy&) { }

Source/WebKit/UIProcess/API/Cocoa/WKDownload.mm

@@ -30,6 +30,7 @@
 #import "CompletionHandlerCallChecker.h"
 #import "DownloadProxy.h"
 #import "WKDownloadDelegate.h"
+#import "WKDownloadDelegatePrivate.h"
 #import "WKFrameInfoInternal.h"
 #import "WKNSData.h"
 #import "WKNSURLAuthenticationChallenge.h"
@@ -41,12 +42,16 @@
 
 class DownloadClient final : public API::DownloadClient {
 public:
-    explicit DownloadClient(id <WKDownloadDelegate> delegate)
+    explicit DownloadClient(id<WKDownloadDelegatePrivate> delegate)
         : m_delegate(delegate)
         , m_respondsToWillPerformHTTPRedirection([delegate respondsToSelector:@selector(download:willPerformHTTPRedirection:newRequest:decisionHandler:)])
         , m_respondsToDidReceiveAuthenticationChallenge([delegate respondsToSelector:@selector(download:didReceiveAuthenticationChallenge:completionHandler:)])
         , m_respondsToDidFinish([m_delegate respondsToSelector:@selector(downloadDidFinish:)])
         , m_respondsToDidFailWithError([delegate respondsToSelector:@selector(download:didFailWithError:resumeData:)])
+#if HAVE(MODERN_DOWNLOADPROGRESS)
+        , m_respondsToDecidePlaceholderPolicy([delegate respondsToSelector:@selector(_download:decidePlaceholderPolicy:)])
+#endif
+
     {
         ASSERT([delegate respondsToSelector:@selector(download:decideDestinationUsingResponse:suggestedFilename:completionHandler:)]);
     }
@@ -142,6 +147,30 @@ void decideDestinationWithSuggestedFilename(WebKit::DownloadProxy& download, con
         }).get()];
     }
 
+#if HAVE(MODERN_DOWNLOADPROGRESS)
+    void decidePlaceholderPolicy(WebKit::DownloadProxy& download, CompletionHandler<void(WebKit::UseDownloadPlaceholder)>&& completionHandler)
+    {
+        if (!m_respondsToDecidePlaceholderPolicy) {
+            completionHandler(WebKit::UseDownloadPlaceholder::No);
+            return;
+        }
+        [m_delegate _download:wrapper(download) decidePlaceholderPolicy:makeBlockPtr([completionHandler = WTFMove(completionHandler)] (_WKPlaceholderPolicy policy) mutable {
+            switch (policy) {
+            case _WKPlaceholderPolicyDisable: {
+                completionHandler(WebKit::UseDownloadPlaceholder::No);
+                break;
+            }
+            case _WKPlaceholderPolicyEnable: {
+                completionHandler(WebKit::UseDownloadPlaceholder::Yes);
+                break;
+            }
+            default:
+                [NSException raise:NSInvalidArgumentException format:@"Invalid WKPlaceholderPolicy (%ld)", (long)policy];
+            }
+        }).get()];
+    }
+#endif
+
     void didReceiveData(WebKit::DownloadProxy& download, uint64_t, uint64_t totalBytesWritten, uint64_t totalBytesExpectedToWrite) final
     {
         NSProgress *progress = wrapper(download).progress;
@@ -173,12 +202,15 @@ void processDidCrash(WebKit::DownloadProxy& download) final
         [m_delegate download:wrapper(download) didFailWithError:[NSError errorWithDomain:NSURLErrorDomain code:NSURLErrorNetworkConnectionLost userInfo:nil] resumeData:nil];
     }
 
-    WeakObjCPtr<id <WKDownloadDelegate> > m_delegate;
+    WeakObjCPtr<id<WKDownloadDelegatePrivate>> m_delegate;
 
     bool m_respondsToWillPerformHTTPRedirection : 1;
     bool m_respondsToDidReceiveAuthenticationChallenge : 1;
     bool m_respondsToDidFinish : 1;
     bool m_respondsToDidFailWithError : 1;
+#if HAVE(MODERN_DOWNLOADPROGRESS)
+    bool m_respondsToDecidePlaceholderPolicy : 1;
+#endif
 };
 
 @implementation WKDownload
@@ -219,7 +251,7 @@ - (WKFrameInfo *)originatingFrame
     return _delegate.get().get();
 }
 
-- (void)setDelegate:(id <WKDownloadDelegate>)delegate
+- (void)setDelegate:(id<WKDownloadDelegatePrivate>)delegate
 {
     _delegate = delegate;
     _download->setClient(adoptRef(*new DownloadClient(delegate)));

Source/WebKit/UIProcess/API/Cocoa/WKDownloadDelegatePrivate.h

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2024 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import <Foundation/Foundation.h>
+#import <WebKit/WKDownloadDelegate.h>
+#import <WebKit/WKFoundation.h>
+
+@class WKDownload;
+
+/* @enum _WKPlaceholderPolicy
+ @abstract The policy for creating a placeholder file in the Downloads directory during downloads.
+ @constant _WKPlaceholderPolicyDisable   Do not create a placeholder file.
+ @constant _WKPlaceholderPolicyEnable    Create a placeholder file.
+ */
+typedef NS_ENUM(NSInteger, _WKPlaceholderPolicy) {
+    _WKPlaceholderPolicyDisable,
+    _WKPlaceholderPolicyEnable,
+} NS_SWIFT_NAME(WKDownload.PlaceholderPolicy) WK_API_AVAILABLE(macos(WK_MAC_TBA), ios(WK_IOS_TBA));
+
+NS_ASSUME_NONNULL_BEGIN
+
+WK_SWIFT_UI_ACTOR
+@protocol WKDownloadDelegatePrivate <WKDownloadDelegate>
+
+@optional
+
+/* @abstract Invoked when the download needs a placeholder policy from the client.
+ @param download The download for which we need a placeholder policy
+ @param completionHandler The completion handler that should be invoked with the chosen policy
+ @discussion The placeholder policy specifies whether a placeholder file should be created in
+ the Downloads directory when the download is in progress.
+ */
+- (void)_download:(WKDownload *)download decidePlaceholderPolicy:(void (^)(_WKPlaceholderPolicy))completionHandler WK_API_AVAILABLE(macos(WK_MAC_TBA), ios(WK_IOS_TBA));
+
+@end
+
+NS_ASSUME_NONNULL_END

Source/WebKit/UIProcess/API/Cocoa/_WKDownload.mm

@@ -79,7 +79,9 @@ - (void)cancel
 
 - (void)publishProgressAtURL:(NSURL *)URL
 {
+#if !HAVE(MODERN_DOWNLOADPROGRESS)
     _download->_download->publishProgress(URL);
+#endif
 }
 
 - (NSURLRequest *)request