Bug 1744484 [wpt PR 31906] - Fix Chrome-specific wpt resize-observer …

…test, a=testonly

Automatic update from web-platform-tests
Fix Chrome-specific wpt resize-observer test

Chrome DCHECKs when testRunner.notifyDone is called
from within ResizeObserver callback.

Initially, I wanted to fix this inside Chrome's
testRunner, but:
- the testRunner fix is not trivial
- these types of bugs are ResizeObserver callback specific
- only occur when DCHECK is turned on

This CL fixes the wpt test instead.
This is much simpler, and we do not expect this
to happen often enough to warrant C++ work.

Bug: 1270820, 626703, 1275806
Change-Id: I0fbedb866998829d7b225ec8f09f5bdb4b7c8238
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3317248
Auto-Submit: Aleks Totic <atotic@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/main@{#948824}

--

wpt-commits: 99384c14df81e8cfeab1ad020c5d3a9691188404
wpt-pr: 31906

testing/web-platform/tests/resize-observer/iframe-same-origin.html

@@ -64,6 +64,10 @@
         // |observerCallbacks| is 3 now.
       });
     });
+  }).then(() => {
+    // This is needed to workaround a Chromium test infrastructure bug.
+    // See https://crbug.com/1270820#c8 for details.
+    return new Promise((resolve) => window.requestAnimationFrame(resolve));
   }).then(() => {
     document.body.offsetHeight; // force to reflow the outer document.
     takeScreenshot();