From 074447e5019b4e147ec126f6a0ff838317fec5c7 Mon Sep 17 00:00:00 2001
From: Alan Jeffrey <ajeffrey@mozilla.com>
Date: Thu, 14 Dec 2017 16:48:19 -0600
Subject: [PATCH] Add a topLevelDomComplete metric.

---
 components/script/document_loader.rs           |  7 +++++++
 components/script/dom/document.rs              | 12 ++++++++++++
 components/script/dom/performancetiming.rs     |  6 ++++++
 .../dom/webidls/PerformanceTiming.webidl       |  3 +++
 tests/wpt/mozilla/meta/MANIFEST.json           | 10 ++++++++++
 ...ow_performance_topLevelDomComplete.html.ini |  3 +++
 ...window_performance_topLevelDomComplete.html | 18 ++++++++++++++++++
 7 files changed, 59 insertions(+)
 create mode 100644 tests/wpt/mozilla/meta/mozilla/window_performance_topLevelDomComplete.html.ini
 create mode 100644 tests/wpt/mozilla/tests/mozilla/window_performance_topLevelDomComplete.html

diff --git a/components/script/document_loader.rs b/components/script/document_loader.rs
index 9fa1f251dbc0..6761f175a3fb 100644
--- a/components/script/document_loader.rs
+++ b/components/script/document_loader.rs
@@ -141,6 +141,13 @@ impl DocumentLoader {
         !self.blocking_loads.is_empty()
     }
 
+    pub fn is_only_blocked_by_iframes(&self) -> bool {
+        self.blocking_loads.iter().all(|load| match *load {
+            LoadType::Subframe(_) => true,
+            _ => false
+        })
+    }
+
     pub fn inhibit_events(&mut self) {
         self.events_inhibited = true;
     }
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 2c27450b29b6..75a54e5c6b9c 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -322,6 +322,7 @@ pub struct Document {
     dom_content_loaded_event_start: Cell<u64>,
     dom_content_loaded_event_end: Cell<u64>,
     dom_complete: Cell<u64>,
+    top_level_dom_complete: Cell<u64>,
     load_event_start: Cell<u64>,
     load_event_end: Cell<u64>,
     /// <https://html.spec.whatwg.org/multipage/#concept-document-https-state>
@@ -1627,6 +1628,12 @@ impl Document {
         // asap_in_order_script_loaded.
 
         let loader = self.loader.borrow();
+
+        // Servo measures when the top-level content (not iframes) is loaded.
+        if (self.top_level_dom_complete.get() == 0) && loader.is_only_blocked_by_iframes() {
+            update_with_current_time_ms(&self.top_level_dom_complete);
+        }
+
         if loader.is_blocked() || loader.events_inhibited() {
             // Step 6.
             return;
@@ -1951,6 +1958,10 @@ impl Document {
         self.dom_complete.get()
     }
 
+    pub fn get_top_level_dom_complete(&self) -> u64 {
+        self.top_level_dom_complete.get()
+    }
+
     pub fn get_load_event_start(&self) -> u64 {
         self.load_event_start.get()
     }
@@ -2265,6 +2276,7 @@ impl Document {
             dom_content_loaded_event_start: Cell::new(Default::default()),
             dom_content_loaded_event_end: Cell::new(Default::default()),
             dom_complete: Cell::new(Default::default()),
+            top_level_dom_complete: Cell::new(Default::default()),
             load_event_start: Cell::new(Default::default()),
             load_event_end: Cell::new(Default::default()),
             https_state: Cell::new(HttpsState::None),
diff --git a/components/script/dom/performancetiming.rs b/components/script/dom/performancetiming.rs
index 0ede2f69b073..7df8e9d2c767 100644
--- a/components/script/dom/performancetiming.rs
+++ b/components/script/dom/performancetiming.rs
@@ -86,6 +86,12 @@ impl PerformanceTimingMethods for PerformanceTiming {
     fn LoadEventEnd(&self) -> u64 {
         self.document.get_load_event_end()
     }
+
+    // check-tidy: no specs after this line
+    // Servo-only timing for when top-level content (not iframes) is complete
+    fn TopLevelDomComplete(&self) -> u64 {
+        self.document.get_top_level_dom_complete()
+    }
 }
 
 
diff --git a/components/script/dom/webidls/PerformanceTiming.webidl b/components/script/dom/webidls/PerformanceTiming.webidl
index 9186a7c56f40..e11c70114589 100644
--- a/components/script/dom/webidls/PerformanceTiming.webidl
+++ b/components/script/dom/webidls/PerformanceTiming.webidl
@@ -29,4 +29,7 @@ interface PerformanceTiming {
   readonly attribute unsigned long long domComplete;
   readonly attribute unsigned long long loadEventStart;
   readonly attribute unsigned long long loadEventEnd;
+  /* Servo-onnly attribute for measuring when the top-level document (not iframes) is complete. */
+  [Pref="dom.testperf.enabled"]
+  readonly attribute unsigned long long topLevelDomComplete;
 };
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 1bd5d50b9b9b..5d1837401179 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -40195,6 +40195,12 @@
      {}
     ]
    ],
+   "mozilla/window_performance_topLevelDomComplete.html": [
+    [
+     "/_mozilla/mozilla/window_performance_topLevelDomComplete.html",
+     {}
+    ]
+   ],
    "mozilla/window_requestAnimationFrame.html": [
     [
      "/_mozilla/mozilla/window_requestAnimationFrame.html",
@@ -72342,6 +72348,10 @@
    "f03283e68b82d972ad21f674243070643ef89489",
    "testharness"
   ],
+  "mozilla/window_performance_topLevelDomComplete.html": [
+   "4b953e63ffa6bf4ed1bc9a2baaea457d46502b9d",
+   "testharness"
+  ],
   "mozilla/window_requestAnimationFrame.html": [
    "86310f3e4b88cce70ef92b56e4f65f034999096e",
    "testharness"
diff --git a/tests/wpt/mozilla/meta/mozilla/window_performance_topLevelDomComplete.html.ini b/tests/wpt/mozilla/meta/mozilla/window_performance_topLevelDomComplete.html.ini
new file mode 100644
index 000000000000..ac65905cb3df
--- /dev/null
+++ b/tests/wpt/mozilla/meta/mozilla/window_performance_topLevelDomComplete.html.ini
@@ -0,0 +1,3 @@
+[window_performance_topLevelDomComplete.html]
+  type: testharness
+  prefs: [dom.testperf.enabled:true]
diff --git a/tests/wpt/mozilla/tests/mozilla/window_performance_topLevelDomComplete.html b/tests/wpt/mozilla/tests/mozilla/window_performance_topLevelDomComplete.html
new file mode 100644
index 000000000000..ce2431a7279e
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/window_performance_topLevelDomComplete.html
@@ -0,0 +1,18 @@
+<html>
+<head>
+  <title>Performance toLevelDomComplete</title>
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+</head>
+<body>
+<script>
+async_test(function(t) {
+  window.onload = t.step_func(function() {
+    assert_true(performance.timing.domLoading <= performance.timing.topLevelDomComplete);
+    assert_true(performance.timing.topLevelDomComplete <= performance.timing.domComplete);
+    t.done();
+  });
+}, "performance.topLevelDomComplete");
+</script>
+</body>
+</html>