[Sheriff] Disable flaky MultipleTabsPlayPause test for other platforms.

Bug: 1157263
Change-Id: I0a02c2db8ec6a68f0fe2dec26269d72db9d9653e
Tbr: mlamouri@google.com
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2587208Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Commit-Queue: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836356}

content/browser/media/session/media_session_browsertest.cc

@@ -333,13 +333,9 @@ IN_PROC_BROWSER_TEST_F(MediaSessionBrowserTest, MAYBE_WebContents_Muted) {
 #if !defined(OS_ANDROID)
 // On Android, System Audio Focus would break this test.
 
-// Flaky on Linux (at least). http://crbug.com/1157263
-#if defined(OS_LINUX)
-#define MAYBE_MultipleTabsPlayPause DISABLED_MultipleTabsPlayPause
-#else
-#define MAYBE_MultipleTabsPlayPause MultipleTabsPlayPause
-#endif
-IN_PROC_BROWSER_TEST_F(MediaSessionBrowserTest, MAYBE_MultipleTabsPlayPause) {
+// Flaky: http://crbug.com/1157263
+IN_PROC_BROWSER_TEST_F(MediaSessionBrowserTest,
+                       DISABLED_MultipleTabsPlayPause) {
   Shell* other_shell = CreateBrowser();
 
   EXPECT_TRUE(NavigateToURL(shell(),