Introduce dynamic ablation of AutocompleteProviders using AC dynamic trials.

chrome/browser/autocomplete/autocomplete_field_trial_unittest.cc

+// Copyright (c) 2013 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 "chrome/browser/autocomplete/autocomplete_field_trial.h"
+
+#include "base/basictypes.h"
+#include "base/metrics/field_trial.h"
+#include "base/string16.h"
+#include "chrome/common/metrics/entropy_provider.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class AutocompleteFieldTrialTest : public testing::Test {
+ public:
+  AutocompleteFieldTrialTest() {}
+
+  static void SetUpTestCase() {
+    ResetFieldTrialList();
+  }
+
+  static void TearDownTestCase() {
+    delete field_trial_list_;
+    field_trial_list_ = NULL;
+  }
+
+  static void ResetFieldTrialList() {
+    // It's important to delete the old pointer first which sets
+    // FieldTrialList::global_ to NULL.
+    if (field_trial_list_)
+      delete field_trial_list_;
+    field_trial_list_ = new base::FieldTrialList(
+        new metrics::SHA1EntropyProvider("foo"));
+    AutocompleteFieldTrial::ActivateDynamicTrials();
+  }
+
+  // Creates and activates a field trial.
+  static base::FieldTrial* CreateTestTrial(const std::string& name,
+                                           const std::string& group_name) {
+    base::FieldTrial* trial = base::FieldTrialList::CreateFieldTrial(
+        name, group_name);
+    trial->group();
+    return trial;
+  }
+
+ private:
+  // Needed for Activate{Static/Dynamic}Trials().
+  static base::FieldTrialList* field_trial_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(AutocompleteFieldTrialTest);
+};
+
+// static
+base::FieldTrialList* AutocompleteFieldTrialTest::field_trial_list_ = NULL;
+
+// Test if GetDisabledProviderTypes() properly parses various field trial
+// group names.
+TEST_F(AutocompleteFieldTrialTest, GetDisabledProviderTypes) {
+  EXPECT_EQ(0, AutocompleteFieldTrial::GetDisabledProviderTypes());
+
+  {
+    SCOPED_TRACE("Invalid groups");
+    CreateTestTrial("AutocompleteDynamicTrial_0", "DisabledProviders_");
+    EXPECT_EQ(0, AutocompleteFieldTrial::GetDisabledProviderTypes());
+    ResetFieldTrialList();
+    CreateTestTrial("AutocompleteDynamicTrial_1", "DisabledProviders_XXX");
+    EXPECT_EQ(0, AutocompleteFieldTrial::GetDisabledProviderTypes());
+    ResetFieldTrialList();
+    CreateTestTrial("AutocompleteDynamicTrial_1", "DisabledProviders_12abc");
+    EXPECT_EQ(0, AutocompleteFieldTrial::GetDisabledProviderTypes());
+  }
+
+  {
+    SCOPED_TRACE("Valid group name, unsupported trial name.");
+    ResetFieldTrialList();
+    CreateTestTrial("UnsupportedTrialName", "DisabledProviders_20");
+    EXPECT_EQ(0, AutocompleteFieldTrial::GetDisabledProviderTypes());
+  }
+
+  {
+    SCOPED_TRACE("Valid field and group name.");
+    ResetFieldTrialList();
+    CreateTestTrial("AutocompleteDynamicTrial_2", "DisabledProviders_3");
+    EXPECT_EQ(3, AutocompleteFieldTrial::GetDisabledProviderTypes());
+    // Two groups should be OR-ed together.
+    CreateTestTrial("AutocompleteDynamicTrial_3", "DisabledProviders_6");
+    EXPECT_EQ(7, AutocompleteFieldTrial::GetDisabledProviderTypes());
+  }
+}