Adding UMA to track previews opt outs and blacklist eligibility

components/previews/core/previews_black_list_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/previews/core/previews_black_list.h"
 
 #include <memory>
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/field_trial.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/test/histogram_tester.h"
 #include "base/test/simple_test_clock.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/previews/core/previews_black_list_item.h"
 #include "components/previews/core/previews_experiments.h"
 #include "components/previews/core/previews_opt_out_store.h"
 #include "components/variations/variations_associated_data.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
 
@@ skipping 80 matching lines @@
                                            params) &&
       base::FieldTrialList::CreateFieldTrial("ClientSidePreviews", "Enabled"));
 
   base::SimpleTestClock* test_clock = new base::SimpleTestClock();
   base::Time start = test_clock->Now();
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
   std::unique_ptr<PreviewsBlackList> black_list(
       new PreviewsBlackList(nullptr, base::WrapUnique(test_clock)));
 
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(url_a, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_a, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(url_b, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->ClearBlackList(start, test_clock->Now());
 
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   variations::testing::ClearAllVariationParams();
 }
 
 TEST_F(PreviewsBlackListTest, PerHostBlackListWithStore) {
   // Tests the black list behavior when a non-null OptOutSture is passed in.
   const GURL url_a1("http://www.url_a.com/a1");
   const GURL url_a2("http://www.url_a.com/a2");
   const GURL url_b("http://www.url_b.com");
   const size_t per_host_history = 4;
@@ skipping 27 matching lines @@
 
   base::SimpleTestClock* test_clock = new base::SimpleTestClock();
   base::Time start = test_clock->Now();
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
   TestPreviewsOptOutStore* opt_out_store = new TestPreviewsOptOutStore();
 
   std::unique_ptr<PreviewsBlackList> black_list(new PreviewsBlackList(
       base::WrapUnique(opt_out_store), base::WrapUnique(test_clock)));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+            black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   base::RunLoop().RunUntilIdle();
 
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(url_a1, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_a1, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(url_b, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   EXPECT_EQ(0, opt_out_store->clear_blacklist_count());
   black_list->ClearBlackList(start, base::Time::Now());
   EXPECT_EQ(1, opt_out_store->clear_blacklist_count());
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+            black_list->IsLoadedAndAllowed(url_a2, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(1, opt_out_store->clear_blacklist_count());
 
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a1, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
 
   variations::testing::ClearAllVariationParams();
 }
 
 TEST_F(PreviewsBlackListTest, HostIndifferentBlackList) {
   // Tests the black list behavior when a null OptOutSture is passed in.
   const GURL urls[] = {
       GURL("http://www.url_0.com"), GURL("http://www.url_1.com"),
       GURL("http://www.url_2.com"), GURL("http://www.url_3.com"),
   };
@@ skipping 22 matching lines @@
       variations::AssociateVariationParams("ClientSidePreviews", "Enabled",
                                            params) &&
       base::FieldTrialList::CreateFieldTrial("ClientSidePreviews", "Enabled"));
 
   base::SimpleTestClock* test_clock = new base::SimpleTestClock();
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
   std::unique_ptr<PreviewsBlackList> black_list(
       new PreviewsBlackList(nullptr, base::WrapUnique(test_clock)));
 
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[1], PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[2], PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[3], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[1], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[2], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[3], PreviewsType::OFFLINE));
 
   for (size_t i = 0; i < host_indifferent_threshold; i++) {
     black_list->AddPreviewNavigation(urls[i], true, PreviewsType::OFFLINE);
-    EXPECT_EQ(i != 3,
+    EXPECT_EQ(i != 3 ? PreviewsEligibilityReason::ALLOWED
+                     : PreviewsEligibilityReason::USER_BLACKLISTED,
               black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
   }
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(urls[1], PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(urls[2], PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(urls[3], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(urls[1], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(urls[2], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(urls[3], PreviewsType::OFFLINE));
 
   black_list->AddPreviewNavigation(urls[3], false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
 
   // New non-opt-out entry will cause these to be allowed now.
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[1], PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[2], PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(urls[3], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[0], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[1], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[2], PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(urls[3], PreviewsType::OFFLINE));
 
   variations::testing::ClearAllVariationParams();
 }
 
 TEST_F(PreviewsBlackListTest, QueueBehavior) {
   // Tests the black list asynchronous queue behavior. Methods called while
   // loading the opt-out store are queued and should run in the order they were
   // queued.
   const GURL url("http://www.url.com");
   const GURL url2("http://www.url2.com");
@@ skipping 25 matching lines @@
 
   for (auto opt_out : test_opt_out) {
     base::SimpleTestClock* test_clock = new base::SimpleTestClock();
     base::Time start = test_clock->Now();
 
     TestPreviewsOptOutStore* opt_out_store = new TestPreviewsOptOutStore();
 
     std::unique_ptr<PreviewsBlackList> black_list(new PreviewsBlackList(
         base::WrapUnique(opt_out_store), base::WrapUnique(test_clock)));
 
-    EXPECT_FALSE(black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
+    EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+              black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
     black_list->AddPreviewNavigation(url, opt_out, PreviewsType::OFFLINE);
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
     black_list->AddPreviewNavigation(url, opt_out, PreviewsType::OFFLINE);
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
-    EXPECT_FALSE(black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
+    EXPECT_EQ(PreviewsEligibilityReason::BLACKLIST_DATA_NOT_LOADED,
+              black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
     base::RunLoop().RunUntilIdle();
-    EXPECT_EQ(!opt_out,
+    EXPECT_EQ(opt_out ? PreviewsEligibilityReason::HOST_BLACKLISTED
+                      : PreviewsEligibilityReason::ALLOWED,
               black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
     black_list->AddPreviewNavigation(url, opt_out, PreviewsType::OFFLINE);
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
     black_list->AddPreviewNavigation(url, opt_out, PreviewsType::OFFLINE);
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
     EXPECT_EQ(0, opt_out_store->clear_blacklist_count());
     black_list->ClearBlackList(
         start, test_clock->Now() + base::TimeDelta::FromSeconds(1));
     EXPECT_EQ(1, opt_out_store->clear_blacklist_count());
     black_list->AddPreviewNavigation(url2, opt_out, PreviewsType::OFFLINE);
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
     black_list->AddPreviewNavigation(url2, opt_out, PreviewsType::OFFLINE);
     test_clock->Advance(base::TimeDelta::FromSeconds(1));
     base::RunLoop().RunUntilIdle();
     EXPECT_EQ(1, opt_out_store->clear_blacklist_count());
 
-    EXPECT_TRUE(black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
-    EXPECT_EQ(!opt_out,
+    EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+              black_list->IsLoadedAndAllowed(url, PreviewsType::OFFLINE));
+    EXPECT_EQ(opt_out ? PreviewsEligibilityReason::HOST_BLACKLISTED
+                      : PreviewsEligibilityReason::ALLOWED,
               black_list->IsLoadedAndAllowed(url2, PreviewsType::OFFLINE));
   }
 
   variations::testing::ClearAllVariationParams();
 }
 
 TEST_F(PreviewsBlackListTest, MaxHosts) {
   // Test that the black list only stores n hosts, and it stores the correct n
   // hosts.
   const GURL url_a("http://www.url_a.com");
@@ skipping 37 matching lines @@
 
   std::unique_ptr<PreviewsBlackList> black_list(
       new PreviewsBlackList(nullptr, base::WrapUnique(test_clock)));
 
   black_list->AddPreviewNavigation(url_a, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_b, false, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_c, false, PreviewsType::OFFLINE);
   // url_a should stay in the map, since it has an opt out time.
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
 
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_d, true, PreviewsType::OFFLINE);
   test_clock->Advance(base::TimeDelta::FromSeconds(1));
   black_list->AddPreviewNavigation(url_e, true, PreviewsType::OFFLINE);
   // url_d and url_e should remain in the map, but url_a should be evicted.
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_d, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_e, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_d, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::HOST_BLACKLISTED,
+            black_list->IsLoadedAndAllowed(url_e, PreviewsType::OFFLINE));
 
   variations::testing::ClearAllVariationParams();
 }
 
 TEST_F(PreviewsBlackListTest, SingleOptOut) {
   // Test that when a user opts out of a preview, previews won't be shown until
   // |single_opt_out_duration| has elapsed.
   const GURL url_a("http://www.url_a.com");
   const GURL url_b("http://www.url_b.com");
   const GURL url_c("http://www.url_c.com");
@@ skipping 25 matching lines @@
       variations::AssociateVariationParams("ClientSidePreviews", "Enabled",
                                            params) &&
       base::FieldTrialList::CreateFieldTrial("ClientSidePreviews", "Enabled"));
 
   base::SimpleTestClock* test_clock = new base::SimpleTestClock();
 
   std::unique_ptr<PreviewsBlackList> black_list(
       new PreviewsBlackList(nullptr, base::WrapUnique(test_clock)));
 
   black_list->AddPreviewNavigation(url_a, false, PreviewsType::OFFLINE);
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_a, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
 
   test_clock->Advance(
       base::TimeDelta::FromSeconds(single_opt_out_duration + 1));
 
   black_list->AddPreviewNavigation(url_b, true, PreviewsType::OFFLINE);
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_RECENTLY_OPTED_OUT,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_RECENTLY_OPTED_OUT,
+            black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
 
   test_clock->Advance(
       base::TimeDelta::FromSeconds(single_opt_out_duration - 1));
 
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
-  EXPECT_FALSE(black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_RECENTLY_OPTED_OUT,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::USER_RECENTLY_OPTED_OUT,
+            black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
 
   test_clock->Advance(
       base::TimeDelta::FromSeconds(single_opt_out_duration + 1));
 
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
-  EXPECT_TRUE(black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_b, PreviewsType::OFFLINE));
+  EXPECT_EQ(PreviewsEligibilityReason::ALLOWED,
+            black_list->IsLoadedAndAllowed(url_c, PreviewsType::OFFLINE));
 
   variations::testing::ClearAllVariationParams();
 }
 
+TEST_F(PreviewsBlackListTest, AddPreviewUMA) {
+  base::HistogramTester histogram_tester;
+  base::SimpleTestClock* test_clock = new base::SimpleTestClock();
+  const GURL url("http://www.url.com");
+  std::unique_ptr<PreviewsBlackList> black_list(
+      new PreviewsBlackList(nullptr, base::WrapUnique(test_clock)));
+
+  black_list->AddPreviewNavigation(url, false, PreviewsType::OFFLINE);
+  histogram_tester.ExpectUniqueSample("Previews.OptOut.UserOptedOut.Offline", 0,
+                                      1);
+  black_list->AddPreviewNavigation(url, true, PreviewsType::OFFLINE);
+  histogram_tester.ExpectBucketCount("Previews.OptOut.UserOptedOut.Offline", 1,
+                                     1);
+}
+
 }  // namespace previews