Disable SiteEngagementServiceTest.CheckHistograms

... due to flakiness on Builder Linux Tests [1].

[1] https://ci.chromium.org/p/chromium/builders/ci/Linux%20Tests/94497

TBR=dominickn

Bug: 1137759
Change-Id: Ib3fe9800b017b311a32cebad46154aca5323bacd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2466246Reviewed-by: Thiemo Nagel <tnagel@chromium.org>
Commit-Queue: Thiemo Nagel <tnagel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816532}

chrome/browser/engagement/site_engagement_service_unittest.cc

@@ -19,6 +19,7 @@
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/simple_test_clock.h"
 #include "base/values.h"
+#include "build/build_config.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/engagement/site_engagement_helper.h"
 #include "chrome/browser/engagement/site_engagement_metrics.h"
@@ -551,7 +552,14 @@ TEST_F(SiteEngagementServiceTest, LastShortcutLaunch) {
   EXPECT_DOUBLE_EQ(0.0, service_->GetScore(url2));
 }
 
-TEST_F(SiteEngagementServiceTest, CheckHistograms) {
+// Disabled due to flakiness on Builder Linux Tests. crbug.com/1137759
+#if defined(OS_LINUX)
+#define MAYBE_CheckHistograms DISABLED_CheckHistograms
+#else
+#define MAYBE_CheckHistograms CheckHistograms
+#endif
+
+TEST_F(SiteEngagementServiceTest, MAYBE_CheckHistograms) {
   base::HistogramTester histograms;
 
   base::Time current_day = GetReferenceTime();