[Suggestions] Remove support for a Control logging group.

Histograms that are no longer logged:
NewTabPage.MostVisited.client0
NewTabPage.SuggestionsImpression.client0

Field trials that are deprecated: ChromeSuggestions

Cleanup in the tests as well.

TBR=mgiuca
BUG=None
TEST=SuggestionsServiceTest*

Review URL: https://codereview.chromium.org/1030713002

Cr-Commit-Position: refs/heads/master@{#322025}

3 files changed, 0 insertions, 76 deletions

diff --git a/components/suggestions/suggestions_service.cc b/components/suggestions/suggestions_service.cc
index fee193e..dbc7036 100644
--- a/components/suggestions/suggestions_service.cc
+++ b/components/suggestions/suggestions_service.cc
@@ -17,7 +17,6 @@
 #include "components/suggestions/blacklist_store.h"
 #include "components/suggestions/suggestions_store.h"
 #include "components/variations/net/variations_http_header_provider.h"
-#include "components/variations/variations_associated_data.h"
 #include "net/base/escape.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
@@ -51,12 +50,6 @@ void LogResponseState(SuggestionsResponseState state) {
                             RESPONSE_STATE_SIZE);
 }
 
-// Obtains the experiment parameter under the supplied |key|, or empty string
-// if the parameter does not exist.
-std::string GetExperimentParam(const std::string& key) {
-  return variations::GetVariationParamValue(kSuggestionsFieldTrialName, key);
-}
-
 GURL BuildBlacklistRequestURL(const std::string& blacklist_url_prefix,
                               const GURL& candidate_url) {
   return GURL(blacklist_url_prefix +
@@ -88,11 +81,6 @@ const int kSchedulingMaxDelaySec = 5 * 60;
 
 }  // namespace
 
-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";
 const char kSuggestionsBlacklistURLPrefix[] =
@@ -118,12 +106,6 @@ SuggestionsService::SuggestionsService(
 
 SuggestionsService::~SuggestionsService() {}
 
-// static
-bool SuggestionsService::IsControlGroup() {
-  return GetExperimentParam(kSuggestionsFieldTrialControlParam) ==
-      kSuggestionsFieldTrialStateEnabled;
-}
-
 void SuggestionsService::FetchSuggestionsData(
     SyncState sync_state,
     SuggestionsService::ResponseCallback callback) {
diff --git a/components/suggestions/suggestions_service.h b/components/suggestions/suggestions_service.h
index 4128b93..b0d0f4c 100644
--- a/components/suggestions/suggestions_service.h
+++ b/components/suggestions/suggestions_service.h
@@ -37,11 +37,6 @@ namespace suggestions {
 class BlacklistStore;
 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[];
 extern const char kSuggestionsBlacklistURLParam[];
@@ -61,9 +56,6 @@ class SuggestionsService : public KeyedService, public net::URLFetcherDelegate {
       scoped_ptr<BlacklistStore> blacklist_store);
   ~SuggestionsService() override;
 
-  // Whether the user is part of a control group.
-  static bool IsControlGroup();
-
   // Request suggestions data, which will be passed to |callback|. |sync_state|
   // will influence the behavior of this function (see SyncState definition).
   //
diff --git a/components/suggestions/suggestions_service_unittest.cc b/components/suggestions/suggestions_service_unittest.cc
index c6253c7..78ac147 100644
--- a/components/suggestions/suggestions_service_unittest.cc
+++ b/components/suggestions/suggestions_service_unittest.cc
@@ -10,15 +10,11 @@
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/field_trial.h"
-#include "base/strings/utf_string_conversions.h"
 #include "components/suggestions/blacklist_store.h"
 #include "components/suggestions/image_manager.h"
 #include "components/suggestions/proto/suggestions.pb.h"
 #include "components/suggestions/suggestions_store.h"
 #include "components/suggestions/suggestions_utils.h"
-#include "components/variations/entropy_provider.h"
-#include "components/variations/variations_associated_data.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_status_code.h"
 #include "net/url_request/test_url_fetcher_factory.h"
@@ -199,27 +195,6 @@ class SuggestionsServiceTest : public testing::Test {
         io_message_loop_.message_loop_proxy());
   }
 
-  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(
-        new base::FieldTrialList(new metrics::SHA1EntropyProvider("foo")));
-
-    variations::testing::ClearAllVariationParams();
-    std::map<std::string, std::string> params;
-    params[kSuggestionsFieldTrialStateParam] =
-        kSuggestionsFieldTrialStateEnabled;
-    if (control_group) {
-      params[kSuggestionsFieldTrialControlParam] =
-          kSuggestionsFieldTrialStateEnabled;
-    }
-    variations::AssociateVariationParams(kSuggestionsFieldTrialName, "Group1",
-                                         params);
-    field_trial_ = base::FieldTrialList::CreateFieldTrial(
-        kSuggestionsFieldTrialName, "Group1");
-    field_trial_->group();
-  }
-
   void FetchSuggestionsDataHelper(SyncState sync_state) {
     scoped_ptr<SuggestionsService> suggestions_service(
         CreateSuggestionsServiceWithMocks());
@@ -343,32 +318,18 @@ class SuggestionsServiceTest : public testing::Test {
   scoped_refptr<net::TestURLRequestContextGetter> request_context_;
 
  private:
-  scoped_ptr<base::FieldTrialList> field_trial_list_;
-  scoped_refptr<base::FieldTrial> field_trial_;
-
   DISALLOW_COPY_AND_ASSIGN(SuggestionsServiceTest);
 };
 
-TEST_F(SuggestionsServiceTest, IsControlGroup) {
-  EnableFieldTrial(false);
-  EXPECT_FALSE(SuggestionsService::IsControlGroup());
-
-  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);
@@ -387,7 +348,6 @@ TEST_F(SuggestionsServiceTest, FetchSuggestionsDataSyncDisabled) {
 }
 
 TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingError) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -407,7 +367,6 @@ TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingError) {
 }
 
 TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingResponseNotOK) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -436,7 +395,6 @@ TEST_F(SuggestionsServiceTest, IssueRequestIfNoneOngoingResponseNotOK) {
 }
 
 TEST_F(SuggestionsServiceTest, BlacklistURL) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -480,7 +438,6 @@ TEST_F(SuggestionsServiceTest, BlacklistURL) {
 }
 
 TEST_F(SuggestionsServiceTest, BlacklistURLFails) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -496,7 +453,6 @@ 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);
@@ -553,7 +509,6 @@ TEST_F(SuggestionsServiceTest, BlacklistURLRequestFails) {
 }
 
 TEST_F(SuggestionsServiceTest, UndoBlacklistURL) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   EXPECT_TRUE(suggestions_service != NULL);
@@ -590,17 +545,14 @@ 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;
@@ -626,7 +578,6 @@ TEST_F(SuggestionsServiceTest, GetBlacklistedUrl) {
 }
 
 TEST_F(SuggestionsServiceTest, UpdateBlacklistDelay) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   base::TimeDelta initial_delay = suggestions_service->blacklist_delay();
@@ -645,7 +596,6 @@ TEST_F(SuggestionsServiceTest, UpdateBlacklistDelay) {
 }
 
 TEST_F(SuggestionsServiceTest, CheckDefaultTimeStamps) {
-  EnableFieldTrial(false);
   scoped_ptr<SuggestionsService> suggestions_service(
       CreateSuggestionsServiceWithMocks());
   SuggestionsProfile suggestions =