Rewrite LoadExpectation to v1.0.

tracing/tracing/importer/find_load_expectations.html

Index: tracing/tracing/importer/find_load_expectations.html
diff --git a/tracing/tracing/importer/find_load_expectations.html b/tracing/tracing/importer/find_load_expectations.html
index 5a20648834f6e218ada4254bc25dbbefadc88337..490a6fb9eac7af75947a55346a85189742e6d9de 100644
--- a/tracing/tracing/importer/find_load_expectations.html
+++ b/tracing/tracing/importer/find_load_expectations.html
@@ -5,51 +5,112 @@ Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
+<link rel="import" href="/tracing/base/category_util.html">
 <link rel="import" href="/tracing/model/user_model/load_expectation.html">
 
 <script>
 'use strict';
 
 tr.exportTo('tr.importer', function() {
-  // This global instant event marks the start of a navigation.
-  var NAVIGATION_START = 'NavigationTiming navigationStart';
-
-  // This render-process instant event marks the first contentful paint in a
-  // main frame.
-  var FIRST_CONTENTFUL_PAINT_TITLE = 'firstContentfulPaint';
-
-  function findLoadExpectations(modelHelper) {
-    var events = [];
+  /**
+   * Find all events that might be interesting for loading metrics.
+   * Don't worry about grouping or sorting them yet.
+   *
+   * @param {!tr.model.helpers.ChromeModelHelper} modelHelper
+   * @return {tr.model.EventSet}
+   */
+  function findLoadEvents(modelHelper) {
+    var events = new tr.model.EventSet();
     modelHelper.model.iterateAllEvents(function(event) {
-      if ((event.title === NAVIGATION_START) ||
-          (event.title === FIRST_CONTENTFUL_PAINT_TITLE))
+      if (tr.model.um.LoadEvents.isLoadEvent(event))
         events.push(event);
     });
-    events.sort(tr.importer.compareEvents);
+    return events;
+  }
+
+  /**
+   * Find the RenderFrame id for an event.
+   *
+   * @param {!tr.model.Event} event
+   * @return {number}
+   */
+  function findFrameId(event) {
+    var renderFrameSnapshot =
+      tr.model.um.LoadEvents.findRenderFrameSnapshotForEvent(event);
+    if (renderFrameSnapshot)
+      return renderFrameSnapshot.objectInstance.scopedId;
+    return undefined;
+  }
+
+  /**
+   * @param {!tr.model.EventSet} events
+   * @return {tr.model.um.LoadExpectation}
+   */
+  function createLoadExpectation(model, events) {
+    var subtypeName = tr.model.um.LOAD_SUBTYPE_NAMES.SUCCESSFUL;
+    var start = Number.MAX_VALUE;
+    var end = -Number.MAX_VALUE;
 
-    var loads = [];
-    var startEvent = undefined;
     events.forEach(function(event) {
-      if (event.title === NAVIGATION_START) {
-        startEvent = event;
-      } else if (event.title === FIRST_CONTENTFUL_PAINT_TITLE) {
-        if (startEvent) {
-          loads.push(new tr.model.um.LoadExpectation(
-              modelHelper.model, tr.model.um.LOAD_SUBTYPE_NAMES.SUCCESSFUL,
-              startEvent.start, event.start - startEvent.start));
-          startEvent = undefined;
-        }
-      }
+      if (tr.model.um.LoadEvents.isStartEvent(event))
+        start = Math.min(start, event.start);
+
+      if (tr.model.um.LoadEvents.isEndEvent(event))
+        end = Math.max(end, event.end);
+
+      if (tr.model.um.LoadEvents.isFailEvent(event))
+        subtypeName = tr.model.um.LOAD_SUBTYPE_NAMES.FAILED;
     });
 
-    // If the trace ended between navigation start and first contentful paint,
-    // then make a LoadExpectation that ends at the end of the trace.
-    if (startEvent) {
-      loads.push(new tr.model.um.LoadExpectation(
-            modelHelper.model, tr.model.um.LOAD_SUBTYPE_NAMES.SUCCESSFUL,
-            startEvent.start, modelHelper.model.bounds.max - startEvent.start));
-    }
+    if (start === Number.MAX_VALUE)
+      throw new Error('Unable to find Load start event');
+
+    if (end === Number.MAX_VALUE)
+      end = model.bounds.max;
+
+    var load = new tr.model.um.LoadExpectation(
+        model, subtypeName, start, end - start);
+    load.associatedEvents.addEventSet(events);
+    load.sourceEvents.addEventSet(events);
+
+    return load;
+  }
+
+  /**
+   * @param {!tr.model.helpers.ChromeModelHelper} modelHelper
+   * @return {Array.<LoadExpectation>}
+   */
+  function findLoadExpectations(modelHelper) {
+    var events = findLoadEvents(modelHelper);
+    var eventsByFrame = events.getEventsOrganizedByCallback(findFrameId);
+    var loads = [];
+
+    tr.b.iterItems(eventsByFrame, function(frameId, frameEvents) {
+      frameEvents = frameEvents.toArray().sort(tr.importer.compareEvents);
+
+      var currentLoadEvents = new tr.model.EventSet();
+      var foundEndEvent = false;
+
+      frameEvents.forEach(function(event) {
+        if (tr.model.um.LoadEvents.isStartEvent(event)) {
+          if ((currentLoadEvents.length > 0) &&
+              foundEndEvent) {
+            loads.push(createLoadExpectation(
+                modelHelper.model, currentLoadEvents));
+            currentLoadEvents = new tr.model.EventSet();
+            foundEndEvent = false;
+          }
+        } else if (tr.model.um.LoadEvents.isEndEvent(event)) {
+          foundEndEvent = true;
+        }
+        currentLoadEvents.push(event);
+      });
+
+      if (currentLoadEvents.length > 0)
+        loads.push(createLoadExpectation(modelHelper.model, currentLoadEvents));
+    });
 
+    loads.sort(tr.importer.compareEvents);
     return loads;
   }