Re-enable MemoryTracingTest.BrowserInitiatedDump for TSAN

Threading issues have been fixed. Re-enabling.

Bug: 529678
Change-Id: Ie8b0a3ed0821bc388f678f45b418e75794e3a063
Reviewed-on: https://chromium-review.googlesource.com/c/1336490Reviewed-by: ssid <ssid@chromium.org>
Commit-Queue: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609002}

content/browser/tracing/memory_tracing_browsertest.cc

@@ -334,9 +334,8 @@ IN_PROC_BROWSER_TEST_F(SingleProcessMemoryTracingTest, DISABLED_QueuedDumps) {
 
 #endif  // defined(OS_ANDROID)
 
-// Non-deterministic races under TSan. crbug.com/529678
 // Flaky on Mac. crbug.com/809809
-#if defined(THREAD_SANITIZER) || defined(OS_MACOSX)
+#if defined(OS_MACOSX)
 #define MAYBE_BrowserInitiatedDump DISABLED_BrowserInitiatedDump
 #else
 #define MAYBE_BrowserInitiatedDump BrowserInitiatedDump