Disable MemoryTracingBrowserTest.TestMemoryInfra on Mac

Disabled due to flaky timeouts.

TBR=ssid@chromium.org

Bug: 806988
Change-Id: I434fe809dc296ef3af2e47b6978bda8b96e7c681
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2208080Reviewed-by: Thomas Lukaszewicz <tluk@chromium.org>
Commit-Queue: Thomas Lukaszewicz <tluk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#769898}

chrome/test/base/memory_tracing_browsertest.cc

@@ -114,8 +114,9 @@ class MemoryTracingBrowserTest : public InProcessBrowserTest {
   bool should_test_memory_dump_success_;
 };
 
-// TODO(crbug.com/806988): Disabled due to excessive output on lsan bots.
-#if defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER)
+// TODO(crbug.com/806988): Disabled due to excessive output on lsan bots and
+// timeouts on Mac Test debug bots.
+#if defined(LEAK_SANITIZER) || defined(ADDRESS_SANITIZER) || defined(OS_MACOSX)
 #define MAYBE_TestMemoryInfra DISABLED_TestMemoryInfra
 #else
 #define MAYBE_TestMemoryInfra TestMemoryInfra