[Extensions] Update FeatureSwitch logic to include Dogfood experiment groups

BUG=591783

Review URL: https://codereview.chromium.org/1757383003

Cr-Commit-Position: refs/heads/master@{#379120}

2 files changed, 84 insertions, 2 deletions

diff --git a/chrome/common/extensions/feature_switch_unittest.cc b/chrome/common/extensions/feature_switch_unittest.cc
index 1f5e608..752e194 100644
--- a/chrome/common/extensions/feature_switch_unittest.cc
+++ b/chrome/common/extensions/feature_switch_unittest.cc
@@ -189,6 +189,38 @@ TEST_F(FeatureSwitchEnabledTest, TrueFieldTrialValue) {
   }
 }
 
+TEST_F(FeatureSwitchEnabledTest, TrueFieldTrialDogfoodValue) {
+  // Construct a fake field trial that defaults to the group "Enabled_Dogfood".
+  base::FieldTrialList field_trials(nullptr);
+  scoped_refptr<base::FieldTrial> enabled_trial =
+      CreateFieldTrial("Enabled_Dogfood");
+  {
+    // A default-enabled switch should be enabled (naturally).
+    FeatureSwitch default_enabled_switch(
+        &command_line_, kSwitchName,
+        std::vector<std::string>(1, kFieldTrialName),
+        FeatureSwitch::DEFAULT_ENABLED);
+    EXPECT_TRUE(default_enabled_switch.IsEnabled());
+    // Scoped overrides override everything.
+    FeatureSwitch::ScopedOverride scoped_override(&default_enabled_switch,
+                                                  false);
+    EXPECT_FALSE(default_enabled_switch.IsEnabled());
+  }
+
+  {
+    // A default-disabled switch should be enabled because of the field trial.
+    FeatureSwitch default_disabled_switch(
+        &command_line_, kSwitchName,
+        std::vector<std::string>(1, kFieldTrialName),
+        FeatureSwitch::DEFAULT_DISABLED);
+    EXPECT_TRUE(default_disabled_switch.IsEnabled());
+    // Scoped overrides override everything.
+    FeatureSwitch::ScopedOverride scoped_override(&default_disabled_switch,
+                                                  false);
+    EXPECT_FALSE(default_disabled_switch.IsEnabled());
+  }
+}
+
 TEST_F(FeatureSwitchEnabledTest, FalseFieldTrialValue) {
   // Construct a fake field trial that defaults to the group "Disabled".
   base::FieldTrialList field_trials(nullptr);
@@ -220,6 +252,54 @@ TEST_F(FeatureSwitchEnabledTest, FalseFieldTrialValue) {
   }
 }
 
+TEST_F(FeatureSwitchEnabledTest, FalseFieldTrialDogfoodValue) {
+  // Construct a fake field trial that defaults to the group "Disabled_Dogfood".
+  base::FieldTrialList field_trials(nullptr);
+  scoped_refptr<base::FieldTrial> disabled_trial =
+      CreateFieldTrial("Disabled_Dogfood");
+  {
+    // A default-enabled switch should be disabled because of the field trial.
+    FeatureSwitch default_enabled_switch(
+        &command_line_, kSwitchName,
+        std::vector<std::string>(1, kFieldTrialName),
+        FeatureSwitch::DEFAULT_ENABLED);
+    EXPECT_FALSE(default_enabled_switch.IsEnabled());
+  }
+
+  {
+    // A default-disabled switch should remain disabled.
+    FeatureSwitch default_disabled_switch(
+        &command_line_, kSwitchName,
+        std::vector<std::string>(1, kFieldTrialName),
+        FeatureSwitch::DEFAULT_DISABLED);
+    EXPECT_FALSE(default_disabled_switch.IsEnabled());
+  }
+}
+
+TEST_F(FeatureSwitchEnabledTest, InvalidGroupFieldTrial) {
+  // Construct a fake field trial that defaults to the group "InvalidGroup".
+  base::FieldTrialList field_trials(nullptr);
+  scoped_refptr<base::FieldTrial> disabled_trial =
+      CreateFieldTrial("InvalidGroup");
+  {
+    // A default-enabled switch should be enabled (the group has no effect).
+    FeatureSwitch default_enabled_switch(
+        &command_line_, kSwitchName,
+        std::vector<std::string>(1, kFieldTrialName),
+        FeatureSwitch::DEFAULT_ENABLED);
+    EXPECT_TRUE(default_enabled_switch.IsEnabled());
+  }
+
+  {
+    // A default-disabled switch should remain disabled.
+    FeatureSwitch default_disabled_switch(
+        &command_line_, kSwitchName,
+        std::vector<std::string>(1, kFieldTrialName),
+        FeatureSwitch::DEFAULT_DISABLED);
+    EXPECT_FALSE(default_disabled_switch.IsEnabled());
+  }
+}
+
 TEST_F(FeatureSwitchEnabledTest,
        TrueFieldTrialValueAndTrueRequiredFieldTrialValue) {
   std::vector<std::string> required_trials;
diff --git a/extensions/common/feature_switch.cc b/extensions/common/feature_switch.cc
index ca73db0..88301f1 100644
--- a/extensions/common/feature_switch.cc
+++ b/extensions/common/feature_switch.cc
@@ -235,9 +235,11 @@ bool FeatureSwitch::IsEnabled() const {
     for (const std::string& field_trial_name : required_field_trials_) {
       std::string group_name =
           base::FieldTrialList::FindFullName(field_trial_name);
-      if (group_name != "Enabled") {
+      if (!base::StartsWith(group_name, "Enabled",
+                            base::CompareCase::SENSITIVE)) {
         enabled_by_field_trial = false;
-        if (group_name == "Disabled") {
+        if (base::StartsWith(group_name, "Disabled",
+                             base::CompareCase::SENSITIVE)) {
           disabled_by_field_trial = true;
           break;
         }