Disable LiveTabCountPageLoadMetricsBrowserTests on MSAN and dbg for flakiness

Tbr: bmcquade@chromium.org
Bug: 1020182
Change-Id: Ice2171c180637bcb9cc601ea889d6ac782526c72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1893140Reviewed-by: Kevin McNee <mcnee@chromium.org>
Commit-Queue: Kevin McNee <mcnee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711299}

chrome/browser/page_load_metrics/observers/live_tab_count_page_load_metrics_observer_browsertest.cc

@@ -60,8 +60,14 @@ class LiveTabCountPageLoadMetricsBrowserTest : public InProcessBrowserTest {
   DISALLOW_COPY_AND_ASSIGN(LiveTabCountPageLoadMetricsBrowserTest);
 };
 
+// TODO(1020182): Flaky for MSAN and dbg.
+#if defined(MEMORY_SANITIZER) || !defined(NDEBUG)
+#define MAYBE_LoadSingleTabInForeground DISABLED_LoadSingleTabInForeground
+#else
+#define MAYBE_LoadSingleTabInForeground LoadSingleTabInForeground
+#endif
 IN_PROC_BROWSER_TEST_F(LiveTabCountPageLoadMetricsBrowserTest,
-                       LoadSingleTabInForeground) {
+                       MAYBE_LoadSingleTabInForeground) {
   BucketCountArray counts = {0};
 
   auto waiter = CreatePageLoadMetricsTestWaiterForForegroundTab();
@@ -78,8 +84,14 @@ IN_PROC_BROWSER_TEST_F(LiveTabCountPageLoadMetricsBrowserTest,
   ValidateHistograms(internal::kHistogramFirstMeaningfulPaintSuffix, counts);
 }
 
+// TODO(1020182): Flaky for MSAN.
+#if defined(MEMORY_SANITIZER)
+#define MAYBE_LoadSingleTabInBackground DISABLED_LoadSingleTabInBackground
+#else
+#define MAYBE_LoadSingleTabInBackground LoadSingleTabInBackground
+#endif
 IN_PROC_BROWSER_TEST_F(LiveTabCountPageLoadMetricsBrowserTest,
-                       LoadSingleTabInBackground) {
+                       MAYBE_LoadSingleTabInBackground) {
   // Open a tab in the background, but don't wait for it to load; we need its
   // WebContents to create a PageLoadMetricsTestWaiter.
   ui_test_utils::NavigateToURLWithDisposition(
@@ -103,8 +115,14 @@ IN_PROC_BROWSER_TEST_F(LiveTabCountPageLoadMetricsBrowserTest,
   ValidateHistograms(internal::kHistogramFirstMeaningfulPaintSuffix, counts);
 }
 
+// TODO(1020182): Flaky for MSAN and dbg.
+#if defined(MEMORY_SANITIZER) || !defined(NDEBUG)
+#define MAYBE_LoadMultipleTabsInForeground DISABLED_LoadMultipleTabsInForeground
+#else
+#define MAYBE_LoadMultipleTabsInForeground LoadMultipleTabsInForeground
+#endif
 IN_PROC_BROWSER_TEST_F(LiveTabCountPageLoadMetricsBrowserTest,
-                       LoadMultipleTabsInForeground) {
+                       MAYBE_LoadMultipleTabsInForeground) {
   // Test opening 5 tabs, which spans the first few buckets.
   constexpr size_t num_test_tabs = 5;