Add a field trial to enable plugin power saver for all users.

R=tommycli@chromium.org,bauerb@chromium.org
BUG=478918

Review URL: https://codereview.chromium.org/1112723002

Cr-Commit-Position: refs/heads/master@{#327546}

3 files changed, 35 insertions, 24 deletions

diff --git a/components/content_settings/core/browser/plugins_field_trial.cc b/components/content_settings/core/browser/plugins_field_trial.cc
index 98cd97a..6452eee 100644
--- a/components/content_settings/core/browser/plugins_field_trial.cc
+++ b/components/content_settings/core/browser/plugins_field_trial.cc
@@ -8,10 +8,15 @@
 #include "base/metrics/field_trial.h"
 #include "components/plugins/common/plugins_switches.h"
 
+using base::FieldTrialList;
+
 namespace content_settings {
 
 // static
-const char PluginsFieldTrial::kFieldTrialName[] = "ForcePluginPowerSaver";
+const char PluginsFieldTrial::kForceFieldTrial[] = "ForcePluginPowerSaver";
+
+// static
+const char PluginsFieldTrial::kEnableFieldTrial[] = "PluginPowerSaver";
 
 // static
 ContentSetting PluginsFieldTrial::EffectiveContentSetting(
@@ -29,14 +34,21 @@ ContentSetting PluginsFieldTrial::EffectiveContentSetting(
 
 // static
 bool PluginsFieldTrial::IsPluginPowerSaverEnabled() {
+  std::string enable_group = FieldTrialList::FindFullName(kEnableFieldTrial);
+  std::string force_group = FieldTrialList::FindFullName(kForceFieldTrial);
+
   const base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
   if (cl->HasSwitch(plugins::switches::kDisablePluginPowerSaver))
     return false;
   if (cl->HasSwitch(plugins::switches::kEnablePluginPowerSaver))
     return true;
 
-  std::string group_name = base::FieldTrialList::FindFullName(kFieldTrialName);
-  return !group_name.empty() && group_name != "Disabled";
+  if (!enable_group.empty() && enable_group != "Disabled")
+    return true;
+  if (!force_group.empty() && force_group != "Disabled")
+    return true;
+
+  return false;
 }
 
 // static
diff --git a/components/content_settings/core/browser/plugins_field_trial.h b/components/content_settings/core/browser/plugins_field_trial.h
index ccc39df..eb7269c 100644
--- a/components/content_settings/core/browser/plugins_field_trial.h
+++ b/components/content_settings/core/browser/plugins_field_trial.h
@@ -14,7 +14,11 @@ namespace content_settings {
 // This class manages the Plugins field trials.
 class PluginsFieldTrial {
  public:
-  static const char kFieldTrialName[];
+  // A legacy field trial used to dogfood Plugin Power Saver. Remove soon.
+  static const char kForceFieldTrial[];
+
+  // The field trial responsible for rolling out Plugin Power Saver to users.
+  static const char kEnableFieldTrial[];
 
   // Returns the effective content setting for plugins. Passes non-plugin
   // content settings through without modification.
diff --git a/components/content_settings/core/browser/plugins_field_trial_unittest.cc b/components/content_settings/core/browser/plugins_field_trial_unittest.cc
index 052f8a5..b052d99 100644
--- a/components/content_settings/core/browser/plugins_field_trial_unittest.cc
+++ b/components/content_settings/core/browser/plugins_field_trial_unittest.cc
@@ -15,18 +15,12 @@
 #include "components/pref_registry/testing_pref_service_syncable.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace content_settings {
-
-namespace {
-
-const auto& kFieldTrialName = PluginsFieldTrial::kFieldTrialName;
+using base::FieldTrialList;
 
-void ForceFieldTrialGroup(const std::string& group_name) {
-  using base::FieldTrialList;
-  ASSERT_TRUE(FieldTrialList::CreateFieldTrial(kFieldTrialName, group_name));
-}
+namespace content_settings {
 
-}  // namespace
+const char* kEnableFieldTrial = PluginsFieldTrial::kEnableFieldTrial;
+const char* kForceFieldTrial = PluginsFieldTrial::kForceFieldTrial;
 
 class PluginsFieldTrialTest : public testing::Test {
  public:
@@ -42,48 +36,49 @@ TEST_F(PluginsFieldTrialTest, DisabledByDefault) {
   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
   ASSERT_FALSE(cl->HasSwitch(plugins::switches::kDisablePluginPowerSaver));
   ASSERT_FALSE(cl->HasSwitch(plugins::switches::kEnablePluginPowerSaver));
-  ASSERT_FALSE(base::FieldTrialList::TrialExists(kFieldTrialName));
+  ASSERT_FALSE(base::FieldTrialList::TrialExists(kEnableFieldTrial));
+  ASSERT_FALSE(base::FieldTrialList::TrialExists(kForceFieldTrial));
   EXPECT_FALSE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
-TEST_F(PluginsFieldTrialTest, FieldTrialEnabled) {
-  ForceFieldTrialGroup("Enabled");
+TEST_F(PluginsFieldTrialTest, EnabledByFieldTrial) {
+  ASSERT_TRUE(FieldTrialList::CreateFieldTrial(kForceFieldTrial, "Dogfood"));
   EXPECT_TRUE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
-TEST_F(PluginsFieldTrialTest, FieldTrialDisabled) {
-  ForceFieldTrialGroup("Disabled");
+TEST_F(PluginsFieldTrialTest, DisabledByFieldTrial) {
+  ASSERT_TRUE(FieldTrialList::CreateFieldTrial(kEnableFieldTrial, "Disabled"));
   EXPECT_FALSE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
-TEST_F(PluginsFieldTrialTest, SwitchEnabled) {
+TEST_F(PluginsFieldTrialTest, EnabledBySwitch) {
   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
   cl->AppendSwitch(plugins::switches::kEnablePluginPowerSaver);
   EXPECT_TRUE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
-TEST_F(PluginsFieldTrialTest, SwitchDisabled) {
+TEST_F(PluginsFieldTrialTest, DisabledBySwitch) {
   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
   cl->AppendSwitch(plugins::switches::kDisablePluginPowerSaver);
   EXPECT_FALSE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
 TEST_F(PluginsFieldTrialTest, SwitchOverridesFieldTrial1) {
-  ForceFieldTrialGroup("Disabled");
+  ASSERT_TRUE(FieldTrialList::CreateFieldTrial(kForceFieldTrial, "Disabled"));
   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
   cl->AppendSwitch(plugins::switches::kEnablePluginPowerSaver);
   EXPECT_TRUE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
 TEST_F(PluginsFieldTrialTest, SwitchOverridesFieldTrial2) {
-  ForceFieldTrialGroup("Enabled");
+  ASSERT_TRUE(FieldTrialList::CreateFieldTrial(kEnableFieldTrial, "Enabled"));
   base::CommandLine* cl = base::CommandLine::ForCurrentProcess();
   cl->AppendSwitch(plugins::switches::kDisablePluginPowerSaver);
   EXPECT_FALSE(PluginsFieldTrial::IsPluginPowerSaverEnabled());
 }
 
 TEST_F(PluginsFieldTrialTest, NoPrefLeftBehind) {
-  ForceFieldTrialGroup("Enabled");
+  ASSERT_TRUE(FieldTrialList::CreateFieldTrial(kEnableFieldTrial, "Enabled"));
   user_prefs::TestingPrefServiceSyncable prefs;
   {
     DefaultProvider::RegisterProfilePrefs(prefs.registry());