[privacy_budget] Deflake UkmEntryFilter tests.

R=caraitto@chromium.org

Bug: 1108942
Change-Id: I2bd72849d79a64d85cb9b61e87efe226d48a0cbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2366662
Auto-Submit: Asanka Herath <asanka@chromium.org>
Reviewed-by: Caleb Raitto <caraitto@chromium.org>
Commit-Queue: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800263}

chrome/browser/privacy_budget/identifiability_study_state.cc

@@ -116,6 +116,11 @@ bool IdentifiabilityStudyState::ShouldSampleSurface(
   return should_record;
 }
 
+// static
+void IdentifiabilityStudyState::ResetStateForTesting() {
+  blink::IdentifiabilityStudySettings::ResetStateForTesting();
+}
+
 // static
 void IdentifiabilityStudyState::InitializeGlobalStudySettings() {
   blink::IdentifiabilityStudySettings::SetGlobalProvider(

chrome/browser/privacy_budget/identifiability_study_state.h

@@ -59,6 +59,10 @@ class IdentifiabilityStudyState {
   // Calling this method may alter the state of the study settings.
   bool ShouldSampleSurface(blink::IdentifiableSurface surface);
 
+  // Should be called from unit-tests if multiple IdentifiabilityStudyState
+  // instances are to be constructed.
+  static void ResetStateForTesting();
+
   // A knob that we can use to split data sets from different versions of the
   // implementation where the differences could have material effects on the
   // data distribution.

chrome/browser/privacy_budget/privacy_budget_ukm_entry_filter_unittest.cc

@@ -8,6 +8,7 @@
 
 #include "base/containers/flat_map.h"
 #include "base/template_util.h"
+#include "chrome/browser/privacy_budget/identifiability_study_state.h"
 #include "chrome/common/privacy_budget/scoped_privacy_budget_config.h"
 #include "components/prefs/testing_pref_service.h"
 #include "services/metrics/public/cpp/ukm_builders.h"
@@ -35,9 +36,9 @@ class PrivacyBudgetUkmEntryFilterTest : public ::testing::Test {
 
 }  // namespace
 
-// TODO(crbug.com/1117358) Flaky
 TEST(PrivacyBudgetUkmEntryFilterStandaloneTest,
-     DISABLED_BlocksIdentifiabilityMetricsByDefault) {
+     BlocksIdentifiabilityMetricsByDefault) {
+  IdentifiabilityStudyState::ResetStateForTesting();
   TestingPrefServiceSimple pref_service;
   prefs::RegisterPrivacyBudgetPrefs(pref_service.registry());
   auto settings = std::make_unique<IdentifiabilityStudyState>(&pref_service);
@@ -55,8 +56,8 @@ TEST(PrivacyBudgetUkmEntryFilterStandaloneTest,
 }
 
 // TODO(crbug.com/1117358) Flaky
-TEST(PrivacyBudgetUkmEntryFilterStandaloneTest,
-     DISABLED_AllowsOtherMetricsByDefault) {
+TEST(PrivacyBudgetUkmEntryFilterStandaloneTest, AllowsOtherMetricsByDefault) {
+  IdentifiabilityStudyState::ResetStateForTesting();
   TestingPrefServiceSimple pref_service;
   prefs::RegisterPrivacyBudgetPrefs(pref_service.registry());
   auto settings = std::make_unique<IdentifiabilityStudyState>(&pref_service);