Tracing: disable a flaky test on all platforms

Bug: 832981
Change-Id: I230384753592e4397d164460a9cc953c17b10daf
Reviewed-on: https://chromium-review.googlesource.com/1033343Reviewed-by: oysteine <oysteine@chromium.org>
Commit-Queue: Ehsan Chiniforooshan <chiniforooshan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#554508}

chrome/browser/tracing/chrome_tracing_delegate_browsertest.cc

@@ -295,13 +295,8 @@ IN_PROC_BROWSER_TEST_F(ChromeTracingDelegateBrowserTestOnStartup,
 }
 
 // https://crbug.com/832981
-#if defined(OS_CHROMEOS)
-#define MAYBE_StartupTracingThrottle DISABLED_StartupTracingThrottle
-#else
-#define MAYBE_StartupTracingThrottle StartupTracingThrottle
-#endif
 IN_PROC_BROWSER_TEST_F(ChromeTracingDelegateBrowserTestOnStartup,
-                       MAYBE_StartupTracingThrottle) {
+                       DISABLED_StartupTracingThrottle) {
   // The startup scenario should *not* be started, since not enough
   // time has elapsed since the last upload (set in the PRE_ above).
   EXPECT_FALSE(