Auto merge of #17735 - ferjm:navigationstart, r=jdm

Set navigation start value according to navigation timing spec

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #17651

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2 files changed, 17 insertions, 7 deletions

diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 27bd4f10004..2d95efbc294 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -3659,6 +3659,8 @@ impl DocumentMethods for Document {
         // Step 10.
         // TODO: prompt to unload.
 
+        window_from_node(self).set_navigation_start();
+
         // Step 11.
         // TODO: unload.
 
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 487bf48eaba..3c87e5f6b0b 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -184,8 +184,8 @@ pub struct Window {
     history: MutNullableJS<History>,
     custom_element_registry: MutNullableJS<CustomElementRegistry>,
     performance: MutNullableJS<Performance>,
-    navigation_start: u64,
-    navigation_start_precise: f64,
+    navigation_start: Cell<u64>,
+    navigation_start_precise: Cell<f64>,
     screen: MutNullableJS<Screen>,
     session_storage: MutNullableJS<Storage>,
     local_storage: MutNullableJS<Storage>,
@@ -702,8 +702,8 @@ impl WindowMethods for Window {
     // NavigationTiming/Overview.html#sec-window.performance-attribute
     fn Performance(&self) -> Root<Performance> {
         self.performance.or_init(|| {
-            Performance::new(self, self.navigation_start,
-                             self.navigation_start_precise)
+            Performance::new(self, self.navigation_start.get(),
+                             self.navigation_start_precise.get())
         })
     }
 
@@ -1772,6 +1772,13 @@ impl Window {
     pub fn unminified_js_dir(&self) -> Option<String> {
         self.unminified_js_dir.borrow().clone()
     }
+
+    pub fn set_navigation_start(&self) {
+        let current_time = time::get_time();
+        let now = (current_time.sec * 1000 + current_time.nsec as i64 / 1000000) as u64;
+        self.navigation_start.set(now);
+        self.navigation_start_precise.set(time::precise_time_ns() as f64);
+    }
 }
 
 impl Window {
@@ -1799,6 +1806,8 @@ impl Window {
                parent_info: Option<(PipelineId, FrameType)>,
                window_size: Option<WindowSizeData>,
                origin: MutableOrigin,
+               navigation_start: u64,
+               navigation_start_precise: f64,
                webvr_thread: Option<IpcSender<WebVRMsg>>)
                -> Root<Window> {
         let layout_rpc: Box<LayoutRPC + Send> = {
@@ -1810,7 +1819,6 @@ impl Window {
             pipelineid: id,
             script_chan: Arc::new(Mutex::new(control_chan)),
         };
-        let current_time = time::get_time();
         let win = box Window {
             globalscope:
                 GlobalScope::new_inherited(
@@ -1837,8 +1845,8 @@ impl Window {
             window_proxy: Default::default(),
             document: Default::default(),
             performance: Default::default(),
-            navigation_start: (current_time.sec * 1000 + current_time.nsec as i64 / 1000000) as u64,
-            navigation_start_precise: time::precise_time_ns() as f64,
+            navigation_start: Cell::new(navigation_start),
+            navigation_start_precise: Cell::new(navigation_start_precise),
             screen: Default::default(),
             session_storage: Default::default(),
             local_storage: Default::default(),