[sheriff] Disable CompositingScaleFactorInNestedFrameTest

The test is flaky.

TBR=sunnyps@chromium.org

Bug: 1164391
Change-Id: Icb6902cbad5e898c9abae14f46d69e83b004aa1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2637554Reviewed-by: Rainhard Findling <rainhard@chromium.org>
Commit-Queue: Rainhard Findling <rainhard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844731}

content/browser/site_per_process_browsertest.cc

@@ -13239,8 +13239,9 @@ IN_PROC_BROWSER_TEST_P(
 
 // Test that the compositing scale factor for an out-of-process iframe are set
 // and updated correctly, including accounting for all intermediate transforms.
+// TODO(crbug.com/1164391): Flaky test.
 IN_PROC_BROWSER_TEST_P(SitePerProcessBrowserTest,
-                       CompositingScaleFactorInNestedFrameTest) {
+                       DISABLED_CompositingScaleFactorInNestedFrameTest) {
   GURL main_url(embedded_test_server()->GetURL(
       "a.com", "/frame_tree/page_with_scaled_frame.html"));
   EXPECT_TRUE(NavigateToURL(shell(), main_url));