LibWeb: Save document load timing when creating browsing context

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -269,6 +269,7 @@ set(SOURCES
     HTML/WorkerGlobalScope.cpp
     HTML/WorkerLocation.cpp
     HTML/WorkerNavigator.cpp
+    HighResolutionTime/CoarsenTime.cpp
     HighResolutionTime/Performance.cpp
     Infra/ByteSequences.cpp
     IntersectionObserver/IntersectionObserver.cpp

Userland/Libraries/LibWeb/HTML/BrowsingContext.cpp

@@ -19,6 +19,7 @@
 #include <LibWeb/HTML/SandboxingFlagSet.h>
 #include <LibWeb/HTML/Scripting/WindowEnvironmentSettingsObject.h>
 #include <LibWeb/HTML/Window.h>
+#include <LibWeb/HighResolutionTime/CoarsenTime.h>
 #include <LibWeb/Layout/BreakNode.h>
 #include <LibWeb/Layout/InitialContainingBlock.h>
 #include <LibWeb/Layout/TextNode.h>
@@ -158,8 +159,12 @@ NonnullRefPtr<BrowsingContext> BrowsingContext::create_a_new_browsing_context(Pa
         top_level_creation_url,
         top_level_origin);
 
-    // FIXME: 12. Let loadTimingInfo be a new document load timing info with its navigation start time set to the result of calling
+    // 12. Let loadTimingInfo be a new document load timing info with its navigation start time set to the result of calling
-    //            coarsen time with unsafeContextCreationTime and the new environment settings object's cross-origin isolated capability.
+    //     coarsen time with unsafeContextCreationTime and the new environment settings object's cross-origin isolated capability.
+    auto load_timing_info = DOM::DocumentLoadTimingInfo();
+    load_timing_info.navigation_start_time = HighResolutionTime::coarsen_time(
+        unsafe_context_creation_time,
+        verify_cast<WindowEnvironmentSettingsObject>(window->realm().host_defined())->cross_origin_isolated_capability() == CanUseCrossOriginIsolatedAPIs::Yes);
 
     // 13. Let coop be a new cross-origin opener policy.
     auto coop = CrossOriginOpenerPolicy {};
@@ -179,7 +184,7 @@ NonnullRefPtr<BrowsingContext> BrowsingContext::create_a_new_browsing_context(Pa
     //     FIXME: active sandboxing flag set is sandboxFlags,
     //     FIXME: permissions policy is permissionsPolicy,
     //     cross-origin opener policy is coop,
-    //     FIXME: load timing info is loadTimingInfo,
+    //     load timing info is loadTimingInfo,
     //     FIXME: navigation id is null,
     //     and which is ready for post-load tasks.
     auto document = DOM::Document::create(*window);
@@ -193,6 +198,7 @@ NonnullRefPtr<BrowsingContext> BrowsingContext::create_a_new_browsing_context(Pa
     document->set_origin(origin);
     document->set_url(AK::URL("about:blank"));
     document->set_cross_origin_opener_policy(coop);
+    document->set_load_timing_info(load_timing_info);
     document->set_ready_for_post_load_tasks(true);
 
     // FIXME: 16. Assert: document's URL and document's relevant settings object's creation URL are about:blank.

Userland/Libraries/LibWeb/HighResolutionTime/CoarsenTime.cpp

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/HighResolutionTime/CoarsenTime.h>
+
+namespace Web::HighResolutionTime {
+
+// https://w3c.github.io/hr-time/#dfn-coarsen-time
+double coarsen_time(double timestamp, bool cross_origin_isolated_capability)
+{
+    // FIXME: Implement this.
+    (void)cross_origin_isolated_capability;
+    return timestamp;
+}
+
+}

Userland/Libraries/LibWeb/HighResolutionTime/CoarsenTime.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+namespace Web::HighResolutionTime {
+
+// https://w3c.github.io/hr-time/#dfn-coarsen-time
+double coarsen_time(double timestamp, bool cross_origin_isolated_capability = false);
+
+}