Disable flaky SmsBrowserTest.AtMostOnePendingSmsRequest

On win it's also flaky with the same error:
https://ci.chromium.org/p/chromium/builders/ci/Win10%20Tests%20x64/39888

TBR=juncai@chromium.org

Bug: 997549
Change-Id: I5a6464aba2edff9d397581d103a1cc0d3548b772
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1768534Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690376}

content/browser/sms/sms_browsertest.cc

@@ -130,7 +130,8 @@ IN_PROC_BROWSER_TEST_F(SmsBrowserTest, Receive) {
   ExpectOutcomeUKM(url, blink::SMSReceiverOutcome::kSuccess);
 }
 
-IN_PROC_BROWSER_TEST_F(SmsBrowserTest, AtMostOnePendingSmsRequest) {
+// Flaky. crbug.com/997549
+IN_PROC_BROWSER_TEST_F(SmsBrowserTest, DISABLED_AtMostOnePendingSmsRequest) {
   GURL url = GetTestUrl(nullptr, "simple_page.html");
   NavigateToURL(shell(), url);