Bug 1685829 - Migrate test_interrupted_reflow.html to async/await style. r=botond

Depends on D101282

Differential Revision: https://phabricator.services.mozilla.com/D101283

gfx/layers/apz/test/mochitest/test_interrupted_reflow.html

@@ -594,7 +594,7 @@ function getAsyncScrollOffsets(aPaintsToIgnore) {
   return offsets;
 }
 
-function* test(testDriver) {
+async function test() {
   var utils = SpecialPowers.DOMWindowUtils;
 
   // The APZ test data accumulates whenever a test turns it on. We just want
@@ -609,9 +609,8 @@ function* test(testDriver) {
 
   var maxScroll = elm.scrollTopMax;
   elm.scrollTop = maxScroll;
-  yield waitForAllPaints(function() {
-    flushApzRepaints(testDriver);
-  });
+  await promiseAllPaintsDone();
+  await promiseApzRepaintsFlushed();
 
   // Take control of the refresh driver
   utils.advanceTimeAndRefresh(0);
@@ -628,7 +627,7 @@ function* test(testDriver) {
   utils.advanceTimeAndRefresh(0);
   // On android, and maybe non-e10s platforms generally, we need to manually
   // kick the paint to send the layer transaction to the compositor.
-  yield waitForAllPaints(function() { setTimeout(testDriver, 0); });
+  await promiseAllPaintsDone();
 
   // Read the main-thread scroll offset; although this is temporarily 0,0 that
   // temporary value is never exposed to content - instead reading this value
@@ -639,7 +638,7 @@ function* test(testDriver) {
   // .. and now flush everything to make sure the state gets pushed over to the
   // compositor and APZ as well.
   utils.restoreNormalRefresh();
-  yield waitForApzFlushedRepaints(testDriver);
+  await promiseApzFlushedRepaints();
 
   // Now we pull the compositor data and check it. What we expect to see is that
   // the scroll position goes to maxScroll, then drops to 0 and then goes back
@@ -710,7 +709,7 @@ if (isApzEnabled()) {
   pushPrefs([["apz.test.logging_enabled", true],
              ["apz.displayport_expiry_ms", 0]])
   .then(waitUntilApzStable)
-  .then(runContinuation(test))
+  .then(test)
   .then(SimpleTest.finish, SimpleTest.finishWithFailure);
 }