Disable flaky PropagateUserGestureFlag test.

SitePerProcessAutoplayBrowserTest.PropagateUserGestureFlag is flaky.

TBR=mlamouri@chromium.org

Bug: 1014175
Change-Id: I0de4853597b0c6b1060218838c3278a43a67efc3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1860678Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705631}

content/browser/site_per_process_browsertest.cc

@@ -4160,8 +4160,9 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessBrowserTest, OriginReplication) {
 
 // Test that HasReceivedUserGesture and HasReceivedUserGestureBeforeNavigation
 // are propagated correctly across origins.
+// Flaky. https://crbug.com/1014175
 IN_PROC_BROWSER_TEST_F(SitePerProcessAutoplayBrowserTest,
-                       PropagateUserGestureFlag) {
+                       DISABLED_PropagateUserGestureFlag) {
   GURL main_url(embedded_test_server()->GetURL(
       "example.com", "/media/autoplay/autoplay-enabled.html"));
   GURL foo_url(embedded_test_server()->GetURL(