Bug 1240044 - wait for MozAfterPaint in browser_profiler_tree_abstract tests on CLOSED TREE;r=bgrins

While waiting for a fix at test harness level, added a helper waiting for MozAfterPaint
when running in e10s mode for all the browser_profiler_tree-abstract tests.

--HG--
extra : commitid : CvYNKvoSNBl

devtools/client/performance/test/browser.ini

@@ -132,7 +132,6 @@ skip-if = os == 'linux' || debug # bug 1186322 for Linux, bug 1203895 for leaks
 [browser_perf-telemetry-03.js]
 [browser_perf-telemetry-04.js]
 [browser_profiler_tree-abstract-01.js]
-skip-if = e10s && os == 'linux' # bug 1186322
 [browser_profiler_tree-abstract-02.js]
 [browser_profiler_tree-abstract-03.js]
 [browser_profiler_tree-abstract-04.js]

devtools/client/performance/test/browser_profiler_tree-abstract-01.js

@@ -11,7 +11,7 @@ var { Heritage } = Cu.import("resource://devtools/client/shared/widgets/ViewHelp
 
 function* spawnTest() {
   let container = document.createElement("vbox");
-  gBrowser.selectedBrowser.parentNode.appendChild(container);
+  yield appendAndWaitForPaint(gBrowser.selectedBrowser.parentNode, container);
 
   // Populate the tree and test the root item...
 

devtools/client/performance/test/browser_profiler_tree-abstract-02.js

@@ -11,10 +11,9 @@ var { Heritage } = Cu.import("resource://devtools/client/shared/widgets/ViewHelp
 
 function* spawnTest() {
   let container = document.createElement("vbox");
-  gBrowser.selectedBrowser.parentNode.appendChild(container);
+  yield appendAndWaitForPaint(gBrowser.selectedBrowser.parentNode, container);
 
   // Populate the tree and test `expand`, `collapse` and `getChild`...
-
   let treeRoot = new MyCustomTreeItem(gDataSrc, { parent: null });
   treeRoot.autoExpandDepth = 1;
   treeRoot.attachTo(container);

devtools/client/performance/test/browser_profiler_tree-abstract-03.js

@@ -11,7 +11,7 @@ var { Heritage } = Cu.import("resource://devtools/client/shared/widgets/ViewHelp
 
 function* spawnTest() {
   let container = document.createElement("vbox");
-  gBrowser.selectedBrowser.parentNode.appendChild(container);
+  yield appendAndWaitForPaint(gBrowser.selectedBrowser.parentNode, container);
 
   // Populate the tree by pressing RIGHT...
 

devtools/client/performance/test/browser_profiler_tree-abstract-04.js

@@ -10,7 +10,7 @@ var { Heritage } = Cu.import("resource://devtools/client/shared/widgets/ViewHelp
 
 function* spawnTest() {
   let container = document.createElement("vbox");
-  gBrowser.selectedBrowser.parentNode.appendChild(container);
+  yield appendAndWaitForPaint(gBrowser.selectedBrowser.parentNode, container);
 
   // Populate the tree and test the root item...
 

devtools/client/performance/test/head.js

@@ -206,6 +206,37 @@ function onceSpread(aTarget, aEventName, aUseCapture) {
   return once(aTarget, aEventName, aUseCapture, true);
 }
 
+/**
+ * Returns a promise that will resolve when the window triggers a MozAfterPaint
+ * event. This ensures the current tab has been painted.
+ * @return {Promise}
+ */
+function waitForMozAfterPaint() {
+  return new Promise(resolve => {
+    let onMozAfterPaint = function() {
+      window.removeEventListener("MozAfterPaint", onMozAfterPaint);
+      resolve();
+    };
+    window.addEventListener("MozAfterPaint", onMozAfterPaint);
+  });
+}
+
+/**
+ * Appends the provided element to the provided parent node. If run in e10s
+ * mode, will also wait for MozAfterPaint to make sure the tab is rendered.
+ * Should be reviewed if Bug 1240509 lands
+ */
+function* appendAndWaitForPaint(parent, element) {
+  let isE10s = Services.appinfo.browserTabsRemoteAutostart;
+  if (isE10s) {
+    let onMozAfterPaint = waitForMozAfterPaint();
+    parent.appendChild(element);
+    return onMozAfterPaint;
+  }
+
+  parent.appendChild(element);
+}
+
 function test () {
   Task.spawn(spawnTest).then(finish, handleError);
 }