Transfer remote page map to SuspendedPageProxy when suspending

https://bugs.webkit.org/show_bug.cgi?id=259148
rdar://112143525

Reviewed by J Pascoe.

When navigating from one page that has iframes to another, we use the remote page map
to broadcast frame tree updates.  We shouldn't broadcast to remote pages associated
with the suspended page.  The main frame is transferred, and now the remote page map
is transferred along with it.

The RemotePageDrawingAreaProxy needs to ignore a few drawing messages after it suspends.
These should be ignored because it is not longer drawing after it suspends, and the
drawing area has been destroyed.  SuspendedPageProxy also ignores messages it doesn't
recognize with no assertion.

When navigating to a SuspendedPageProxy, we need to restore the remote page map.
The remote page map follows the path of the main frame through the ProvisionalPageProxy
back to the WebPageProxy.

We were hitting assertions because the CachedFrame constructor would only remove LocalFrames.
To make it not assert, remove all Frames.  We still need to implement CachedFrame for
RemoteFrames, but this makes the test cover much of the navigation back to a SuspendedPageProxy
without assertion, with future work still to be done.

This change enables opening several popular news websites with site isolation on without asserting.

* Source/WebKit/UIProcess/RemotePageDrawingAreaProxy.cpp:
(WebKit::RemotePageDrawingAreaProxy::didReceiveMessage):
* Source/WebKit/UIProcess/SuspendedPageProxy.cpp:
(WebKit::SuspendedPageProxy::SuspendedPageProxy):
* Source/WebKit/UIProcess/SuspendedPageProxy.h:
* Source/WebKit/UIProcess/WebPageProxy.cpp:
(WebKit::WebPageProxy::takeRemotePageMap):
* Source/WebKit/UIProcess/WebPageProxy.h:
* Tools/TestWebKitAPI/Tests/WebKitCocoa/SiteIsolation.mm:
(TestWebKitAPI::TEST):

Canonical link: https://commits.webkit.org/266018@main

Source/WebCore/history/CachedFrame.cpp

@@ -185,8 +185,11 @@ CachedFrame::CachedFrame(LocalFrame& frame)
     // We do this for two reasons:
     // 1 - We reuse the main frame, so when it navigates to a new page load it needs to start with a blank FrameTree.
     // 2 - It's much easier to destroy a CachedFrame while it resides in the BackForwardCache if it is disconnected from its parent.
-    for (unsigned i = 0; i < m_childFrames.size(); ++i)
-        frame.tree().removeChild(m_childFrames[i]->view()->frame());
+    Vector<Ref<Frame>> children;
+    for (auto* child = frame.tree().firstChild(); child; child = child->tree().nextSibling())
+        children.append(*child);
+    for (auto& child : children)
+        frame.tree().removeChild(child);
 
 #ifndef NDEBUG
     if (m_isMainFrame)

Source/WebKit/UIProcess/ProvisionalPageProxy.cpp

@@ -103,6 +103,7 @@ ProvisionalPageProxy::ProvisionalPageProxy(WebPageProxy& page, Ref<WebProcessPro
         ASSERT(&suspendedPage->process() == m_process.ptr());
         suspendedPage->unsuspend();
         m_mainFrame = &suspendedPage->mainFrame();
+        m_remotePageMap = suspendedPage->takeRemotePageMap();
     }
 
     initializeWebPage(websitePolicies);
@@ -152,6 +153,11 @@ void ProvisionalPageProxy::setNavigation(API::Navigation& navigation)
     navigation.setProcessID(m_process->coreProcessIdentifier());
 }
 
+std::optional<HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>>> ProvisionalPageProxy::takeRemotePageMap()
+{
+    return std::exchange(m_remotePageMap, std::nullopt);
+}
+
 void ProvisionalPageProxy::cancel()
 {
     // If the provisional load started, then indicate that it failed due to cancellation by calling didFailProvisionalLoadForFrame().

Source/WebKit/UIProcess/ProvisionalPageProxy.h

@@ -50,13 +50,15 @@ class FormDataReference;
 }
 
 namespace WebCore {
+class RegistrableDomain;
 class ResourceRequest;
 enum class ShouldTreatAsContinuingLoad : uint8_t;
 }
 
 namespace WebKit {
 
 class DrawingAreaProxy;
+class RemotePageProxy;
 class SuspendedPageProxy;
 class UserData;
 class WebBackForwardListItem;
@@ -90,6 +92,7 @@ class ProvisionalPageProxy : public IPC::MessageReceiver, public IPC::MessageSen
     ProcessSwapRequestedByClient processSwapRequestedByClient() const { return m_processSwapRequestedByClient; }
     uint64_t navigationID() const { return m_navigationID; }
     const URL& provisionalURL() const { return m_provisionalLoadURL; }
+    std::optional<HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>>> takeRemotePageMap();
 
     bool isProcessSwappingOnNavigationResponse() const { return m_isProcessSwappingOnNavigationResponse; }
 
@@ -202,6 +205,7 @@ class ProvisionalPageProxy : public IPC::MessageReceiver, public IPC::MessageSen
     LayerHostingContextID m_contextIDForVisibilityPropagationInGPUProcess { 0 };
 #endif
 #endif
+    std::optional<HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>>> m_remotePageMap;
 };
 
 } // namespace WebKit

Source/WebKit/UIProcess/RemotePageDrawingAreaProxy.cpp

@@ -52,8 +52,6 @@ void RemotePageDrawingAreaProxy::didReceiveMessage(IPC::Connection& connection,
 {
     if (m_drawingArea)
         m_drawingArea->didReceiveMessage(connection, decoder);
-    else
-        ASSERT_NOT_REACHED();
 }
 
 bool RemotePageDrawingAreaProxy::didReceiveSyncMessage(IPC::Connection& connection, IPC::Decoder& decoder, UniqueRef<IPC::Encoder>& encoder)

Source/WebKit/UIProcess/SuspendedPageProxy.cpp

@@ -111,6 +111,7 @@ SuspendedPageProxy::SuspendedPageProxy(WebPageProxy& page, Ref<WebProcessProxy>&
     , m_contextIDForVisibilityPropagationInGPUProcess(page.contextIDForVisibilityPropagationInGPUProcess())
 #endif
 #endif
+    , m_remotePageMap(page.takeRemotePageMap())
 {
     allSuspendedPages().add(this);
     m_process->addSuspendedPageProxy(*this);
@@ -138,6 +139,11 @@ SuspendedPageProxy::~SuspendedPageProxy()
     m_process->removeSuspendedPageProxy(*this);
 }
 
+HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>> SuspendedPageProxy::takeRemotePageMap()
+{
+    return std::exchange(m_remotePageMap, { });
+}
+
 void SuspendedPageProxy::didDestroyNavigation(uint64_t navigationID)
 {
     m_page.didDestroyNavigationShared(m_process.copyRef(), navigationID);

Source/WebKit/UIProcess/SuspendedPageProxy.h

@@ -41,6 +41,7 @@ class RegistrableDomain;
 
 namespace WebKit {
 
+class RemotePageProxy;
 class WebBackForwardCache;
 class WebPageProxy;
 class WebProcessPool;
@@ -64,6 +65,7 @@ class SuspendedPageProxy final: public IPC::MessageReceiver, public IPC::Message
     WebCore::PageIdentifier webPageID() const { return m_webPageID; }
     WebProcessProxy& process() const { return m_process.get(); }
     WebFrameProxy& mainFrame() { return m_mainFrame.get(); }
+    HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>> takeRemotePageMap();
 
     WebBackForwardCache& backForwardCache() const;
 
@@ -125,6 +127,7 @@ class SuspendedPageProxy final: public IPC::MessageReceiver, public IPC::Message
     LayerHostingContextID m_contextIDForVisibilityPropagationInGPUProcess { 0 };
 #endif
 #endif
+    HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>> m_remotePageMap;
 };
 
 } // namespace WebKit

Source/WebKit/UIProcess/WebPageProxy.cpp

@@ -1140,6 +1140,9 @@ void WebPageProxy::swapToProvisionalPage(std::unique_ptr<ProvisionalPageProxy> p
     ASSERT(!m_mainFrame);
     m_mainFrame = provisionalPage->mainFrame();
 
+    if (auto map = provisionalPage->takeRemotePageMap())
+        internals().domainToRemotePageProxyMap = WTFMove(*map);
+
     m_process->addExistingWebPage(*this, WebProcessProxy::BeginsUsingDataStore::No);
     addAllMessageReceivers();
 
@@ -12662,6 +12665,11 @@ void WebPageProxy::addOpenedRemotePageProxy(Ref<RemotePageProxy>&& page)
     internals().openedRemotePageProxies.add(WTFMove(page));
 }
 
+HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>> WebPageProxy::takeRemotePageMap()
+{
+    return std::exchange(internals().domainToRemotePageProxyMap, { });
+}
+
 #if ENABLE(ADVANCED_PRIVACY_PROTECTIONS)
 
 Vector<LinkDecorationFilteringData>& WebPageProxy::cachedAllowedQueryParametersForAdvancedPrivacyProtections()

Source/WebKit/UIProcess/WebPageProxy.h

@@ -2167,9 +2167,9 @@ class WebPageProxy final : public API::ObjectImpl<API::Object::Type::Page>, publ
     RemotePageProxy* remotePageProxyForRegistrableDomain(WebCore::RegistrableDomain) const;
     void addRemotePageProxy(const WebCore::RegistrableDomain&, WeakPtr<RemotePageProxy>&&);
     void removeRemotePageProxy(const WebCore::RegistrableDomain&);
-
     void setRemotePageProxyInOpenerProcess(Ref<RemotePageProxy>&&);
     void addOpenedRemotePageProxy(Ref<RemotePageProxy>&&);
+    HashMap<WebCore::RegistrableDomain, WeakPtr<RemotePageProxy>> takeRemotePageMap();
 
     void createRemoteSubframesInOtherProcesses(WebFrameProxy&);
 

Tools/TestWebKitAPI/Tests/WebKitCocoa/SiteIsolation.mm

@@ -1096,4 +1096,32 @@ HTTPServer server({
     // FIXME: Call checkFrameTreesInProcesses here and make sure the frames are in reasonable processes.
 }
 
+TEST(SiteIsolation, NavigationWithIFrames)
+{
+    HTTPServer server({
+        { "/1"_s, { "<iframe src='https://domain2.com/2'></iframe>"_s } },
+        { "/2"_s, { "hi!"_s } },
+        { "/3"_s, { "<iframe src='https://domain4.com/4'></iframe>"_s } },
+        { "/4"_s, { "<iframe src='https://domain5.com/5'></iframe>"_s } },
+        { "/5"_s, { "hi!"_s } }
+    }, HTTPServer::Protocol::HttpsProxy);
+
+    auto navigationDelegate = adoptNS([TestNavigationDelegate new]);
+    [navigationDelegate allowAnyTLSCertificate];
+    auto configuration = server.httpsProxyConfiguration();
+    enableSiteIsolation(configuration);
+    auto webView = adoptNS([[WKWebView alloc] initWithFrame:CGRectZero configuration:configuration]);
+    webView.get().navigationDelegate = navigationDelegate.get();
+
+    [webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://domain1.com/1"]]];
+    [navigationDelegate waitForDidFinishNavigation];
+
+    [webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://domain3.com/3"]]];
+    [navigationDelegate waitForDidFinishNavigation];
+
+    [webView goBack];
+    [navigationDelegate waitForDidFinishNavigation];
+    // FIXME: Implement CachedFrame for RemoteFrames and verify the page is resumed correctly.
+}
+
 }