predictors: Remove unused field trial configuration parsing.

chrome/browser/predictors/resource_prefetch_common_unittest.cc

 // Copyright 2014 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 <memory>
+#include <string>
+
+#include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/field_trial.h"
-#include "base/metrics/statistics_recorder.h"
 #include "chrome/browser/net/prediction_options.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
-#include "chrome/browser/predictors/resource_prefetch_predictor_factory.h"
 #include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/ui/browser.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_profile.h"
 #include "components/prefs/pref_service.h"
-#include "components/variations/entropy_provider.h"
 #include "content/public/test/test_browser_thread.h"
 #include "net/base/network_change_notifier.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using chrome_browser_net::NetworkPredictionOptions;
 using net::NetworkChangeNotifier;
 
 namespace {
 
 class MockNetworkChangeNotifierWIFI : public NetworkChangeNotifier {
  public:
   ConnectionType GetCurrentConnectionType() const override {
     return NetworkChangeNotifier::CONNECTION_WIFI;
   }
 };
 
 class MockNetworkChangeNotifier4G : public NetworkChangeNotifier {
  public:
   ConnectionType GetCurrentConnectionType() const override {
     return NetworkChangeNotifier::CONNECTION_4G;
   }
 };
 
-} // namespace
+}  // namespace
 
 namespace predictors {
 
 class ResourcePrefetchCommonTest : public testing::Test {
  public:
   ResourcePrefetchCommonTest();
-  void SetUp() override;
-
-  void CreateTestFieldTrial(const std::string& name,
-                            const std::string& group_name) {
-    base::FieldTrial* trial = base::FieldTrialList::CreateFieldTrial(
-        name, group_name);
-    trial->group();
-  }
 
   void SetPreference(NetworkPredictionOptions value) {
     profile_->GetPrefs()->SetInteger(prefs::kNetworkPredictionOptions, value);
   }
 
-  void TestIsPrefetchDisabled(ResourcePrefetchPredictorConfig& config) {
+  void SetCommandLineValue(const std::string& value) {
+    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+        switches::kSpeculativeResourcePrefetching, value);
+  }
+
+  void TestIsPrefetchDisabled(const ResourcePrefetchPredictorConfig& config) {
     EXPECT_FALSE(config.IsLearningEnabled());
     EXPECT_FALSE(config.IsPrefetchingEnabled(profile_.get()));
     EXPECT_FALSE(config.IsURLLearningEnabled());
     EXPECT_FALSE(config.IsHostLearningEnabled());
     EXPECT_FALSE(config.IsURLPrefetchingEnabled(profile_.get()));
     EXPECT_FALSE(config.IsHostPrefetchingEnabled(profile_.get()));
   }
 
-  void TestIsPrefetchEnabled(ResourcePrefetchPredictorConfig& config) {
+  void TestIsPrefetchEnabled(const ResourcePrefetchPredictorConfig& config) {
     EXPECT_TRUE(config.IsLearningEnabled());
     EXPECT_TRUE(config.IsPrefetchingEnabled(profile_.get()));
     EXPECT_TRUE(config.IsURLLearningEnabled());
     EXPECT_TRUE(config.IsHostLearningEnabled());
     EXPECT_TRUE(config.IsURLPrefetchingEnabled(profile_.get()));
     EXPECT_TRUE(config.IsHostPrefetchingEnabled(profile_.get()));
   }
 
-  void TestIsPrefetchLearning(ResourcePrefetchPredictorConfig& config) {
+  void TestIsPrefetchLearning(const ResourcePrefetchPredictorConfig& config) {
     EXPECT_TRUE(config.IsLearningEnabled());
     EXPECT_FALSE(config.IsPrefetchingEnabled(profile_.get()));
     EXPECT_TRUE(config.IsURLLearningEnabled());
     EXPECT_TRUE(config.IsHostLearningEnabled());
     EXPECT_FALSE(config.IsURLPrefetchingEnabled(profile_.get()));
     EXPECT_FALSE(config.IsHostPrefetchingEnabled(profile_.get()));
   }
 
-  void TestIsDefaultExtraConfig(ResourcePrefetchPredictorConfig& config) {
+  void TestIsDefaultExtraConfig(const ResourcePrefetchPredictorConfig& config) {
     EXPECT_FALSE(config.IsLowConfidenceForTest());
     EXPECT_FALSE(config.IsHighConfidenceForTest());
     EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
     EXPECT_FALSE(config.IsSmallDBEnabledForTest());
   }
 
  protected:
   base::MessageLoop loop_;
   content::TestBrowserThread ui_thread_;
   std::unique_ptr<TestingProfile> profile_;
-
- private:
-  std::unique_ptr<base::FieldTrialList> field_trial_list_;
 };
 
 ResourcePrefetchCommonTest::ResourcePrefetchCommonTest()
     : loop_(base::MessageLoop::TYPE_DEFAULT),
       ui_thread_(content::BrowserThread::UI, &loop_),
       profile_(new TestingProfile()) { }
 
-void ResourcePrefetchCommonTest::SetUp() {
-  field_trial_list_.reset(new base::FieldTrialList(
-      base::MakeUnique<metrics::SHA1EntropyProvider>(
-          "ResourcePrefetchCommonTest")));
-  base::StatisticsRecorder::Initialize();
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialNotSpecified) {
+TEST_F(ResourcePrefetchCommonTest, IsDisabledByDefault) {

[pasko, 2016/11/28 16:31:13]

On related note: I am not sure the clutter around these BlahEnabled() functions
is worth the benefits.  Testing the string parsing separately may be better.

For example, there is ResourcePrefetchPredictorConfig::IsLearningEnabled() that
is used in two places:
1. tests (7 mentions)
2. DCHECK (1 mention)

worth it?

If you feel the same way, let's nuke these too? (no pressure though, can
certainly wait until maintaining them becomes more of a burden)

[Benoit L, 2016/11/28 17:09:55]

This will become a bit more complex with the external only mode being added
later on, so let's keep these for now.

   ResourcePrefetchPredictorConfig config;
   EXPECT_FALSE(
       IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
   TestIsPrefetchDisabled(config);

[pasko, 2016/11/28 16:31:13]

This is becoming the single callsite for this function, which makes the purpose
of the function unclear. Let's inline such functions in the tests themselves?

[Benoit L, 2016/11/28 17:09:55]

Done.

-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingDisabled) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Disabled");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_FALSE(
-      IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchDisabled(config);
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialLearningHost) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Learning:Predictor=Host");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  EXPECT_TRUE(config.IsLearningEnabled());
-  EXPECT_FALSE(config.IsPrefetchingEnabled(profile_.get()));
-  EXPECT_FALSE(config.IsURLLearningEnabled());
-  EXPECT_TRUE(config.IsHostLearningEnabled());
-  EXPECT_FALSE(config.IsURLPrefetchingEnabled(profile_.get()));
-  EXPECT_FALSE(config.IsHostPrefetchingEnabled(profile_.get()));
   TestIsDefaultExtraConfig(config);
 }
 
-TEST_F(ResourcePrefetchCommonTest, FieldTrialLearningURL) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Learning:Predictor=Url");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  EXPECT_TRUE(config.IsLearningEnabled());
-  EXPECT_FALSE(config.IsPrefetchingEnabled(profile_.get()));
-  EXPECT_TRUE(config.IsURLLearningEnabled());
-  EXPECT_FALSE(config.IsHostLearningEnabled());
-  EXPECT_FALSE(config.IsURLPrefetchingEnabled(profile_.get()));
-  EXPECT_FALSE(config.IsHostPrefetchingEnabled(profile_.get()));
-  TestIsDefaultExtraConfig(config);
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialLearning) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Learning");
+TEST_F(ResourcePrefetchCommonTest, EnableLearning) {
+  SetCommandLineValue("learning");
   ResourcePrefetchPredictorConfig config;
   EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
   TestIsPrefetchLearning(config);
   TestIsDefaultExtraConfig(config);
 }
 
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingHost) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:Predictor=Host");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  EXPECT_TRUE(config.IsLearningEnabled());
-  EXPECT_TRUE(config.IsPrefetchingEnabled(profile_.get()));
-  EXPECT_FALSE(config.IsURLLearningEnabled());
-  EXPECT_TRUE(config.IsHostLearningEnabled());
-  EXPECT_FALSE(config.IsURLPrefetchingEnabled(profile_.get()));
-  EXPECT_TRUE(config.IsHostPrefetchingEnabled(profile_.get()));
-  TestIsDefaultExtraConfig(config);
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingURL) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:Predictor=Url");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  EXPECT_TRUE(config.IsLearningEnabled());
-  EXPECT_TRUE(config.IsPrefetchingEnabled(profile_.get()));
-  EXPECT_TRUE(config.IsURLLearningEnabled());
-  EXPECT_FALSE(config.IsHostLearningEnabled());
-  EXPECT_TRUE(config.IsURLPrefetchingEnabled(profile_.get()));
-  EXPECT_FALSE(config.IsHostPrefetchingEnabled(profile_.get()));
-  TestIsDefaultExtraConfig(config);
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetching) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching", "Prefetching=Enabled");
+TEST_F(ResourcePrefetchCommonTest, EnablePrefetch) {
+  SetCommandLineValue("enabled");
   ResourcePrefetchPredictorConfig config;
   EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
   TestIsPrefetchEnabled(config);
   TestIsDefaultExtraConfig(config);
 }
 
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingLowConfidence) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:Confidence=Low");
+
+// Verifies whether prefetching in the field trial is disabled according to

[pasko, 2016/11/28 16:31:13]

Should we remove the mention of the field trial?

[Benoit L, 2016/11/28 17:09:55]

Done.

+// the network type. But learning should not be disabled by network.
+TEST_F(ResourcePrefetchCommonTest, RespectsNetworkSettings) {
+  SetCommandLineValue("enabled");
   ResourcePrefetchPredictorConfig config;
   EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
   TestIsPrefetchEnabled(config);
-  EXPECT_TRUE(config.IsLowConfidenceForTest());
-  EXPECT_FALSE(config.IsHighConfidenceForTest());
-  EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_FALSE(config.IsSmallDBEnabledForTest());
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingHighConfidence) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:Confidence=High");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchEnabled(config);
-  EXPECT_FALSE(config.IsLowConfidenceForTest());
-  EXPECT_TRUE(config.IsHighConfidenceForTest());
-  EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_FALSE(config.IsSmallDBEnabledForTest());
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingMoreResources) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Learning:MoreResources=Enabled");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchLearning(config);
-  EXPECT_FALSE(config.IsLowConfidenceForTest());
-  EXPECT_FALSE(config.IsHighConfidenceForTest());
-  EXPECT_TRUE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_FALSE(config.IsSmallDBEnabledForTest());
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialLearningSmallDB) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Learning:SmallDB=Enabled");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchLearning(config);
-  EXPECT_FALSE(config.IsLowConfidenceForTest());
-  EXPECT_FALSE(config.IsHighConfidenceForTest());
-  EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_TRUE(config.IsSmallDBEnabledForTest());
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingSmallDB) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:SmallDB=Enabled");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchEnabled(config);
-  EXPECT_FALSE(config.IsLowConfidenceForTest());
-  EXPECT_FALSE(config.IsHighConfidenceForTest());
-  EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_TRUE(config.IsSmallDBEnabledForTest());
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingSmallDBLowConfidence) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:SmallDB=Enabled:Confidence=Low");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchEnabled(config);
-  EXPECT_TRUE(config.IsLowConfidenceForTest());
-  EXPECT_FALSE(config.IsHighConfidenceForTest());
-  EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_TRUE(config.IsSmallDBEnabledForTest());
-}
-
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingSmallDBHighConfidence) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled:SmallDB=Enabled:Confidence=High");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchEnabled(config);
-  EXPECT_FALSE(config.IsLowConfidenceForTest());
-  EXPECT_TRUE(config.IsHighConfidenceForTest());
-  EXPECT_FALSE(config.IsMoreResourcesEnabledForTest());
-  EXPECT_TRUE(config.IsSmallDBEnabledForTest());
-}
-
-// Verifies whether prefetching in the field trial is disabled according to
-// the network type. But learning should not be disabled by network.
-TEST_F(ResourcePrefetchCommonTest, FieldTrialPrefetchingDisabledByNetwork) {
-  CreateTestFieldTrial("SpeculativeResourcePrefetching",
-                       "Prefetching=Enabled");
-  ResourcePrefetchPredictorConfig config;
-  EXPECT_TRUE(IsSpeculativeResourcePrefetchingEnabled(profile_.get(), &config));
-  TestIsPrefetchEnabled(config);
+  TestIsDefaultExtraConfig(config);
 
   // Set preference to WIFI_ONLY: prefetch when not on cellular.
   SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_WIFI_ONLY);
   {
     std::unique_ptr<NetworkChangeNotifier> mock(
         new MockNetworkChangeNotifierWIFI);
     TestIsPrefetchEnabled(config);
   }
   {
     std::unique_ptr<NetworkChangeNotifier> mock(
         new MockNetworkChangeNotifier4G);
     TestIsPrefetchLearning(config);
   }
 
   // Set preference to NEVER: never prefetch.
   SetPreference(NetworkPredictionOptions::NETWORK_PREDICTION_NEVER);
   {
     std::unique_ptr<NetworkChangeNotifier> mock(
         new MockNetworkChangeNotifierWIFI);
     TestIsPrefetchLearning(config);
   }
   {
     std::unique_ptr<NetworkChangeNotifier> mock(
         new MockNetworkChangeNotifier4G);
     TestIsPrefetchLearning(config);
   }
 }
 
 }  // namespace predictors