Revert of Moving previews code from components/ to chrome/

components/previews/core/previews_io_data_unittest.cc

Index: components/previews/core/previews_io_data_unittest.cc
diff --git a/components/previews/core/previews_io_data_unittest.cc b/components/previews/core/previews_io_data_unittest.cc
index 23b1bac9a3a2007ad4e929db67761845c9aa64fa..39a8925e618e6667060a5207f816ae47e89a35be 100644
--- a/components/previews/core/previews_io_data_unittest.cc
+++ b/components/previews/core/previews_io_data_unittest.cc
@@ -37,10 +37,6 @@
 
 namespace {
 
-bool CheckOfflineFieldTrial(PreviewsType type) {
-  return previews::params::IsOfflinePreviewsEnabled();
-}
-
 class TestPreviewsIOData : public PreviewsIOData {
  public:
   TestPreviewsIOData(
@@ -129,7 +125,7 @@
   set_io_data(base::MakeUnique<TestPreviewsIOData>(loop_.task_runner(),
                                                    loop_.task_runner()));
   set_ui_service(base::MakeUnique<PreviewsUIService>(
-      io_data(), loop_.task_runner(), nullptr, PreviewsIsEnabledCallback()));
+      io_data(), loop_.task_runner(), nullptr));
   base::RunLoop().RunUntilIdle();
   // After the outstanding posted tasks have run, |io_data_| should be fully
   // initialized.
@@ -148,37 +144,28 @@
                                                    loop_.task_runner()));
   base::HistogramTester histogram_tester;
 
-  // The blacklist is not created yet.
-  EXPECT_FALSE(io_data()->ShouldAllowPreview(*request, PreviewsType::OFFLINE));
-  histogram_tester.ExpectUniqueSample(
-      "Previews.EligibilityReason.Offline",
-      static_cast<int>(PreviewsEligibilityReason::BLACKLIST_UNAVAILABLE), 1);
-
-  set_ui_service(base::MakeUnique<PreviewsUIService>(
-      io_data(), loop_.task_runner(),
-      base::MakeUnique<TestPreviewsOptOutStore>(),
-      base::Bind(&CheckOfflineFieldTrial)));
-
-  // The blacklist is not created yet.
-  EXPECT_FALSE(io_data()->ShouldAllowPreview(*request, PreviewsType::OFFLINE));
-  histogram_tester.ExpectBucketCount(
-      "Previews.EligibilityReason.Offline",
-      static_cast<int>(PreviewsEligibilityReason::BLACKLIST_UNAVAILABLE), 2);
-
-  base::RunLoop().RunUntilIdle();
-
-  histogram_tester.ExpectTotalCount("Previews.EligibilityReason.Offline", 2);
   // If not in the field trial, don't log anything, and return false.
   EXPECT_FALSE(io_data()->ShouldAllowPreview(*request, PreviewsType::OFFLINE));
-  histogram_tester.ExpectTotalCount("Previews.EligibilityReason.Offline", 2);
+  histogram_tester.ExpectTotalCount("Previews.EligibilityReason.Offline", 0);
 
   // Enable Offline previews field trial.
   base::FieldTrialList field_trial_list(nullptr);
   std::map<std::string, std::string> params;
   params["show_offline_pages"] = "true";
-
   variations::AssociateVariationParams("ClientSidePreviews", "Enabled", params);
   base::FieldTrialList::CreateFieldTrial("ClientSidePreviews", "Enabled");
+
+  // The blacklist is not created yet.
+  EXPECT_FALSE(io_data()->ShouldAllowPreview(*request, PreviewsType::OFFLINE));
+  histogram_tester.ExpectUniqueSample(
+      "Previews.EligibilityReason.Offline",
+      static_cast<int>(PreviewsEligibilityReason::BLACKLIST_UNAVAILABLE), 1);
+
+  set_ui_service(base::WrapUnique(
+      new PreviewsUIService(io_data(), loop_.task_runner(),
+                            base::MakeUnique<TestPreviewsOptOutStore>())));
+
+  base::RunLoop().RunUntilIdle();
 
   // Return one of the failing statuses from the blacklist; cause the blacklist
   // to not be loaded by clearing the blacklist.
@@ -240,7 +227,7 @@
       "Previews.EligibilityReason.Offline",
       static_cast<int>(PreviewsEligibilityReason::ALLOWED), 1);
 
-  histogram_tester.ExpectTotalCount("Previews.EligibilityReason.Offline", 8);
+  histogram_tester.ExpectTotalCount("Previews.EligibilityReason.Offline", 7);
 
   variations::testing::ClearAllVariationParams();
 }