[SuggestionsService] Add Variations check for enabling the service

No longer by default for M41.

BUG=450035
TBR=mgiuca

Review URL: https://codereview.chromium.org/855973002

Cr-Commit-Position: refs/heads/master@{#312153}

3 files changed, 34 insertions, 5 deletions

diff --git a/components/suggestions/suggestions_service.cc b/components/suggestions/suggestions_service.cc
index bb47aa1..9c6f2c8 100644
--- a/components/suggestions/suggestions_service.cc
+++ b/components/suggestions/suggestions_service.cc
@@ -91,6 +91,7 @@ const int kSchedulingMaxDelaySec = 5 * 60;
 const char kSuggestionsFieldTrialName[] = "ChromeSuggestions";
 const char kSuggestionsFieldTrialControlParam[] = "control";
 const char kSuggestionsFieldTrialStateEnabled[] = "enabled";
+const char kSuggestionsFieldTrialStateParam[] = "state";
 
 // TODO(mathp): Put this in TemplateURL.
 const char kSuggestionsURL[] = "https://www.google.com/chromesuggestions?t=2";
@@ -118,9 +119,15 @@ SuggestionsService::SuggestionsService(
 SuggestionsService::~SuggestionsService() {}
 
 // static
+bool SuggestionsService::IsEnabled() {
+  return GetExperimentParam(kSuggestionsFieldTrialStateParam) ==
+      kSuggestionsFieldTrialStateEnabled;
+}
+
+// static
 bool SuggestionsService::IsControlGroup() {
   return GetExperimentParam(kSuggestionsFieldTrialControlParam) ==
-         kSuggestionsFieldTrialStateEnabled;
+      kSuggestionsFieldTrialStateEnabled;
 }
 
 void SuggestionsService::FetchSuggestionsData(
diff --git a/components/suggestions/suggestions_service.h b/components/suggestions/suggestions_service.h
index 16c1d60..f4ebfe0 100644
--- a/components/suggestions/suggestions_service.h
+++ b/components/suggestions/suggestions_service.h
@@ -40,6 +40,7 @@ class SuggestionsStore;
 extern const char kSuggestionsFieldTrialName[];
 extern const char kSuggestionsFieldTrialControlParam[];
 extern const char kSuggestionsFieldTrialStateEnabled[];
+extern const char kSuggestionsFieldTrialStateParam[];
 
 extern const char kSuggestionsURL[];
 extern const char kSuggestionsBlacklistURLPrefix[];
@@ -60,6 +61,9 @@ class SuggestionsService : public KeyedService, public net::URLFetcherDelegate {
       scoped_ptr<BlacklistStore> blacklist_store);
   ~SuggestionsService() override;
 
+  // Whether this service is enabled.
+  static bool IsEnabled();
+
   // Whether the user is part of a control group.
   static bool IsControlGroup();
 
diff --git a/components/suggestions/suggestions_service_unittest.cc b/components/suggestions/suggestions_service_unittest.cc
index a2e12e3..c6253c7 100644
--- a/components/suggestions/suggestions_service_unittest.cc
+++ b/components/suggestions/suggestions_service_unittest.cc
@@ -199,8 +199,7 @@ class SuggestionsServiceTest : public testing::Test {
         io_message_loop_.message_loop_proxy());
   }
 
-  // Enables the control group in the "ChromeSuggestions.Group1" field trial.
-  void EnableFieldTrialControlGroup() {
+  void EnableFieldTrial(bool control_group) {
     // Clear the existing |field_trial_list_| to avoid firing a DCHECK.
     field_trial_list_.reset(NULL);
     field_trial_list_.reset(
@@ -208,8 +207,12 @@ class SuggestionsServiceTest : public testing::Test {
 
     variations::testing::ClearAllVariationParams();
     std::map<std::string, std::string> params;
-    params[kSuggestionsFieldTrialControlParam] =
+    params[kSuggestionsFieldTrialStateParam] =
         kSuggestionsFieldTrialStateEnabled;
+    if (control_group) {
+      params[kSuggestionsFieldTrialControlParam] =
+          kSuggestionsFieldTrialStateEnabled;
+    }
     variations::AssociateVariationParams(kSuggestionsFieldTrialName, "Group1",
                                          params);
     field_trial_ = base::FieldTrialList::CreateFieldTrial(
@@ -347,21 +350,25 @@ class SuggestionsServiceTest : public testing::Test {
 };
 
 TEST_F(SuggestionsServiceTest, IsControlGroup) {
+  EnableFieldTrial(false);
   EXPECT_FALSE(SuggestionsService::IsControlGroup());
 
-  EnableFieldTrialControlGroup();
+  EnableFieldTrial(true);
   EXPECT_TRUE(SuggestionsService::IsControlGroup());
 }
 
 TEST_F(SuggestionsServiceTest, FetchSuggestionsData) {
+  EnableFieldTrial(false);
   FetchSuggestionsDataHelper(INITIALIZED_ENABLED_HISTORY);
 }
 
 TEST_F(SuggestionsServiceTest, FetchSuggestionsDataSyncNotInitializedEnabled) {
+  EnableFieldTrial(false);
   FetchSuggestionsDataHelper(NOT_INITIALIZED_ENABLED);
 }
 
 TEST_F(SuggestionsServiceTest, FetchSuggestionsDataSyncDisabled) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -380,6 +387,7 @@ TEST_F(SuggestionsServiceTest, FetchSuggestionsDataSyncDisabled) {
 }
 
 TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingError) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -399,6 +407,7 @@ TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingError) {
 }
 
 TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingResponseNotOK) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -427,6 +436,7 @@ TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingResponseNotOK) {
 }
 
 TEST_F(SuggestionsServiceTest, BlacklistURL) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -470,6 +480,7 @@ TEST_F(SuggestionsServiceTest, BlacklistURL) {
 }
 
 TEST_F(SuggestionsServiceTest, BlacklistURLFails) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -485,6 +496,7 @@ TEST_F(SuggestionsServiceTest, BlacklistURLFails) {
 
 // Initial blacklist request fails, triggering a second which succeeds.
 TEST_F(SuggestionsServiceTest, BlacklistURLRequestFails) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -541,6 +553,7 @@ TEST_F(SuggestionsServiceTest, BlacklistURLRequestFails) {
 }
 
 TEST_F(SuggestionsServiceTest, UndoBlacklistURL) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -577,14 +590,17 @@ TEST_F(SuggestionsServiceTest, UndoBlacklistURL) {
 
 
 TEST_F(SuggestionsServiceTest, UndoBlacklistURLFailsIfNotInBlacklist) {
+  EnableFieldTrial(false);
   UndoBlacklistURLFailsHelper(true);
 }
 
 TEST_F(SuggestionsServiceTest, UndoBlacklistURLFailsIfAlreadyCandidate) {
+  EnableFieldTrial(false);
   UndoBlacklistURLFailsHelper(false);
 }
 
 TEST_F(SuggestionsServiceTest, GetBlacklistedUrl) {
+  EnableFieldTrial(false);
   scoped_ptr<GURL> request_url;
   scoped_ptr<net::FakeURLFetcher> fetcher;
   GURL retrieved_url;
@@ -610,6 +626,7 @@ TEST_F(SuggestionsServiceTest, GetBlacklistedUrl) {
 }
 
 TEST_F(SuggestionsServiceTest, UpdateBlacklistDelay) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   base::TimeDelta initial_delay = suggestions_service->blacklist_delay();
@@ -628,6 +645,7 @@ TEST_F(SuggestionsServiceTest, UpdateBlacklistDelay) {
 }
 
 TEST_F(SuggestionsServiceTest, CheckDefaultTimeStamps) {
+  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   SuggestionsProfile suggestions =