.c Feature to disable field trials in old versions of Chromium. Field trials

tests are (usually) monitored for a fixed length of time. With this change
field trial tests turn them selves off (will use the default group) after
the expiration time (specified in the Field Trial constructor).

BUG=13463
TEST=field_trial_unittests tests this code thorougly. spdy session and testing
     field_trials in renderer process would be very helpful. thanks much.

Review URL: http://codereview.chromium.org/6317004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71820 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 242 insertions, 83 deletions

diff --git a/base/metrics/field_trial.cc b/base/metrics/field_trial.cc
index 654746c..5db88c1 100644
--- a/base/metrics/field_trial.cc
+++ b/base/metrics/field_trial.cc
@@ -7,14 +7,15 @@
 #include "base/logging.h"
 #include "base/rand_util.h"
 #include "base/stringprintf.h"
+#include "base/utf_string_conversions.h"
 
 namespace base {
 
 // static
-const int FieldTrial::kNotParticipating = -1;
+const int FieldTrial::kNotFinalized = -1;
 
 // static
-const int FieldTrial::kAllRemainingProbability = -2;
+const int FieldTrial::kDefaultGroupNumber = 0;
 
 // static
 bool FieldTrial::enable_benchmarking_ = false;
@@ -28,30 +29,53 @@ static const char kHistogramFieldTrialSeparator('_');
 // FieldTrial methods and members.
 
 FieldTrial::FieldTrial(const std::string& name,
-                       const Probability total_probability)
+                       const Probability total_probability,
+                       const std::string& default_group_name,
+                       const int year,
+                       const int month,
+                       const int day_of_month)
   : name_(name),
     divisor_(total_probability),
+    default_group_name_(default_group_name),
     random_(static_cast<Probability>(divisor_ * base::RandDouble())),
     accumulated_group_probability_(0),
-    next_group_number_(0),
-    group_(kNotParticipating) {
+    next_group_number_(kDefaultGroupNumber+1),
+    group_(kNotFinalized) {
+  DCHECK(!default_group_name_.empty());
   FieldTrialList::Register(this);
+
+  DCHECK_GT(year, 1970);
+  DCHECK_GT(month, 0);
+  DCHECK_LT(month, 13);
+  DCHECK_GT(day_of_month, 0);
+  DCHECK_LT(day_of_month, 32);
+
+  base::Time::Exploded exploded;
+  exploded.year = year;
+  exploded.month = month;
+  exploded.day_of_week = 0;  // Should be unusued.
+  exploded.day_of_month = day_of_month;
+  exploded.hour = 0;
+  exploded.minute = 0;
+  exploded.second = 0;
+  exploded.millisecond = 0;
+
+  base::Time expiration_time = Time::FromLocalExploded(exploded);
+  disable_field_trial_ = (GetBuildTime() > expiration_time) ? true : false;
 }
 
 int FieldTrial::AppendGroup(const std::string& name,
                             Probability group_probability) {
   DCHECK(group_probability <= divisor_);
-  DCHECK(group_probability >=0 ||
-         group_probability == kAllRemainingProbability);
-  if (group_probability == kAllRemainingProbability) {
-    accumulated_group_probability_ = divisor_;
-  } else {
-    if (enable_benchmarking_)
-      group_probability = 0;
-    accumulated_group_probability_ += group_probability;
-  }
+  DCHECK_GE(group_probability, 0);
+
+  if (enable_benchmarking_ || disable_field_trial_)
+    group_probability = 0;
+
+  accumulated_group_probability_ += group_probability;
+
   DCHECK(accumulated_group_probability_ <= divisor_);
-  if (group_ == kNotParticipating && accumulated_group_probability_ > random_) {
+  if (group_ == kNotFinalized && accumulated_group_probability_ > random_) {
     // This is the group that crossed the random line, so we do the assignment.
     group_ = next_group_number_;
     if (name.empty())
@@ -62,6 +86,20 @@ int FieldTrial::AppendGroup(const std::string& name,
   return next_group_number_++;
 }
 
+int FieldTrial::group() {
+  if (group_ == kNotFinalized) {
+    accumulated_group_probability_ = divisor_;
+    group_ = kDefaultGroupNumber;
+    group_name_ = default_group_name_;
+  }
+  return group_;
+}
+
+std::string FieldTrial::group_name() {
+  group();  // call group() to make group assignment was done.
+  return group_name_;
+}
+
 // static
 std::string FieldTrial::MakeName(const std::string& name_prefix,
                                  const std::string& trial_name) {
@@ -76,6 +114,16 @@ void FieldTrial::EnableBenchmarking() {
   enable_benchmarking_ = true;
 }
 
+// static
+Time FieldTrial::GetBuildTime() {
+  Time integral_build_time;
+  const char* kDateTime = __DATE__ " " __TIME__;
+  bool result = Time::FromString(ASCIIToWide(kDateTime).c_str(),
+                                 &integral_build_time);
+  DCHECK(result);
+  return integral_build_time;
+}
+
 FieldTrial::~FieldTrial() {}
 
 //------------------------------------------------------------------------------
@@ -129,7 +177,7 @@ int FieldTrialList::FindValue(const std::string& name) {
   FieldTrial* field_trial = Find(name);
   if (field_trial)
     return field_trial->group();
-  return FieldTrial::kNotParticipating;
+  return FieldTrial::kNotFinalized;
 }
 
 // static
@@ -149,9 +197,11 @@ void FieldTrialList::StatesToString(std::string* output) {
   for (RegistrationList::iterator it = global_->registered_.begin();
        it != global_->registered_.end(); ++it) {
     const std::string name = it->first;
-    const std::string group_name = it->second->group_name();
+    std::string group_name = it->second->group_name_internal();
     if (group_name.empty())
-      continue;  // No definitive winner in this trial.
+      // No definitive winner in this trial, use default_group_name as the
+      // group_name.
+      group_name = it->second->default_group_name();
     DCHECK_EQ(name.find(kPersistentStringSeparator), std::string::npos);
     DCHECK_EQ(group_name.find(kPersistentStringSeparator), std::string::npos);
     output->append(name);
@@ -162,34 +212,43 @@ void FieldTrialList::StatesToString(std::string* output) {
 }
 
 // static
-bool FieldTrialList::StringAugmentsState(const std::string& prior_state) {
+bool FieldTrialList::CreateTrialsInChildProcess(
+    const std::string& parent_trials) {
   DCHECK(global_);
-  if (prior_state.empty() || !global_)
+  if (parent_trials.empty() || !global_)
     return true;
 
+  Time::Exploded exploded;
+  Time two_years_from_now =
+      Time::NowFromSystemTime() + TimeDelta::FromDays(730);
+  two_years_from_now.LocalExplode(&exploded);
+  const int kTwoYearsFromNow = exploded.year;
+
   size_t next_item = 0;
-  while (next_item < prior_state.length()) {
-    size_t name_end = prior_state.find(kPersistentStringSeparator, next_item);
-    if (name_end == prior_state.npos || next_item == name_end)
+  while (next_item < parent_trials.length()) {
+    size_t name_end = parent_trials.find(kPersistentStringSeparator, next_item);
+    if (name_end == parent_trials.npos || next_item == name_end)
       return false;
-    size_t group_name_end = prior_state.find(kPersistentStringSeparator,
-                                             name_end + 1);
-    if (group_name_end == prior_state.npos || name_end + 1 == group_name_end)
+    size_t group_name_end = parent_trials.find(kPersistentStringSeparator,
+                                               name_end + 1);
+    if (group_name_end == parent_trials.npos || name_end + 1 == group_name_end)
       return false;
-    std::string name(prior_state, next_item, name_end - next_item);
-    std::string group_name(prior_state, name_end + 1,
+    std::string name(parent_trials, next_item, name_end - next_item);
+    std::string group_name(parent_trials, name_end + 1,
                            group_name_end - name_end - 1);
     next_item = group_name_end + 1;
 
     FieldTrial *field_trial(FieldTrialList::Find(name));
     if (field_trial) {
       // In single process mode, we may have already created the field trial.
-      if (field_trial->group_name() != group_name)
+      if ((field_trial->group_name_internal() != group_name) &&
+          (field_trial->default_group_name() != group_name))
         return false;
       continue;
     }
     const int kTotalProbability = 100;
-    field_trial = new FieldTrial(name, kTotalProbability);
+    field_trial = new FieldTrial(name, kTotalProbability, group_name,
+                                 kTwoYearsFromNow, 1, 1);
     field_trial->AppendGroup(group_name, kTotalProbability);
   }
   return true;
diff --git a/base/metrics/field_trial.h b/base/metrics/field_trial.h
index 8902077..077a88c 100644
--- a/base/metrics/field_trial.h
+++ b/base/metrics/field_trial.h
@@ -66,36 +66,40 @@
 #include <map>
 #include <string>
 
+#include "base/gtest_prod_util.h"
 #include "base/lock.h"
 #include "base/ref_counted.h"
 #include "base/time.h"
 
 namespace base {
 
+class FieldTrialList;
+
 class FieldTrial : public RefCounted<FieldTrial> {
  public:
   typedef int Probability;  // Probability type for being selected in a trial.
 
   // A return value to indicate that a given instance has not yet had a group
   // assignment (and hence is not yet participating in the trial).
-  static const int kNotParticipating;
+  static const int kNotFinalized;
 
-  // Provide an easy way to assign all remaining probability to a group.  Note
-  // that this will force an instance to participate, and make it illegal to
-  // attempt to probabalistically add any other groups to the trial.  When doing
-  // A/B tests with timings, it is often best to define all groups, so that
-  // histograms will get unique names via the MakeName() methods.
-  static const Probability kAllRemainingProbability;
+  // This is the group number of the 'default' group. This provides an easy way
+  // to assign all the remaining probability to a group ('default').
+  static const int kDefaultGroupNumber;
 
   // The name is used to register the instance with the FieldTrialList class,
   // and can be used to find the trial (only one trial can be present for each
   // name).
   // Group probabilities that are later supplied must sum to less than or equal
-  // to the total_probability.
-  FieldTrial(const std::string& name, Probability total_probability);
+  // to the total_probability. Arguments year, month and day_of_month specify
+  // the expiration time. If the build time is after the expiration time then
+  // the field trial reverts to the 'default' group.
+  FieldTrial(const std::string& name, Probability total_probability,
+             const std::string& default_group_name, const int year,
+             const int month, const int day_of_month);
 
   // Establish the name and probability of the next group in this trial.
-  // Sometimes, based on construction randomization, this call may causes the
+  // Sometimes, based on construction randomization, this call may cause the
   // provided group to be *THE* group selected for use in this instance.
   int AppendGroup(const std::string& name, Probability group_probability);
 
@@ -103,14 +107,18 @@ class FieldTrial : public RefCounted<FieldTrial> {
   std::string name() const { return name_; }
 
   // Return the randomly selected group number that was assigned.
-  // Return kNotParticipating if the instance is not participating in the
-  // experiment.
-  int group() const { return group_; }
+  // Return kDefaultGroupNumber if the instance is in the 'default' group.
+  // Note that this will force an instance to participate, and make it illegal
+  // to attempt to probabalistically add any other groups to the trial.
+  int group();
 
   // If the field trial is not in an experiment, this returns the empty string.
   // if the group's name is empty, a name of "_" concatenated with the group
   // number is used as the group name.
-  std::string group_name() const { return group_name_; }
+  std::string group_name();
+
+  // Return the default group name of the FieldTrial.
+  std::string default_group_name() const { return default_group_name_; }
 
   // Helper function for the most common use: as an argument to specifiy the
   // name of a HISTOGRAM.  Use the original histogram name as the name_prefix.
@@ -121,17 +129,40 @@ class FieldTrial : public RefCounted<FieldTrial> {
   static void EnableBenchmarking();
 
  private:
+  // Allow tests to access our innards for testing purposes.
+  FRIEND_TEST(FieldTrialTest, Registration);
+  FRIEND_TEST(FieldTrialTest, AbsoluteProbabilities);
+  FRIEND_TEST(FieldTrialTest, RemainingProbability);
+  FRIEND_TEST(FieldTrialTest, FiftyFiftyProbability);
+  FRIEND_TEST(FieldTrialTest, MiddleProbabilities);
+  FRIEND_TEST(FieldTrialTest, OneWinner);
+  FRIEND_TEST(FieldTrialTest, DisableProbability);
+  FRIEND_TEST(FieldTrialTest, Save);
+  FRIEND_TEST(FieldTrialTest, DuplicateRestore);
+  FRIEND_TEST(FieldTrialTest, MakeName);
+
+  friend class base::FieldTrialList;
+
   friend class RefCounted<FieldTrial>;
 
   virtual ~FieldTrial();
 
+  // Returns the group_name. A winner need not have been chosen.
+  std::string group_name_internal() const { return group_name_; }
+
+  // Get build time.
+  static Time GetBuildTime();
+
   // The name of the field trial, as can be found via the FieldTrialList.
   // This is empty of the trial is not in the experiment.
   const std::string name_;
 
   // The maximum sum of all probabilities supplied, which corresponds to 100%.
   // This is the scaling factor used to adjust supplied probabilities.
-  Probability divisor_;
+  const Probability divisor_;
+
+  // The name of the default group.
+  const std::string default_group_name_;
 
   // The randomly selected probability that is used to select a group (or have
   // the instance not participate).  It is the product of divisor_ and a random
@@ -144,15 +175,19 @@ class FieldTrial : public RefCounted<FieldTrial> {
   int next_group_number_;
 
   // The pseudo-randomly assigned group number.
-  // This is kNotParticipating if no group has been assigned.
+  // This is kNotFinalized if no group has been assigned.
   int group_;
 
-  // A textual name for the randomly selected group, including the Trial name.
-  // If this Trial is not a member of an group, this string is empty.
+  // A textual name for the randomly selected group. If this Trial is not a
+  // member of an group, this string is empty.
   std::string group_name_;
 
+  // When disable_field_trial_ is true, field trial reverts to the 'default'
+  // group.
+  bool disable_field_trial_;
+
   // When benchmarking is enabled, field trials all revert to the 'default'
-  // bucket.
+  // group.
   static bool enable_benchmarking_;
 
   DISALLOW_COPY_AND_ASSIGN(FieldTrial);
@@ -199,7 +234,7 @@ class FieldTrialList {
   // is commonly used in a sub-process, to carry randomly selected state in a
   // parent process into this sub-process.
   //  Currently only the group_name_ and name_ are restored.
-  static bool StringAugmentsState(const std::string& prior_state);
+  static bool CreateTrialsInChildProcess(const std::string& prior_trials);
 
   // The time of construction of the global map is recorded in a static variable
   // and is commonly used by experiments to identify the time since the start
diff --git a/base/metrics/field_trial_unittest.cc b/base/metrics/field_trial_unittest.cc
index a8138bb..0af6d60 100644
--- a/base/metrics/field_trial_unittest.cc
+++ b/base/metrics/field_trial_unittest.cc
@@ -13,7 +13,23 @@ namespace base {
 
 class FieldTrialTest : public testing::Test {
  public:
-  FieldTrialTest() : trial_list_() { }
+  FieldTrialTest() : trial_list_() {
+    Time now = Time::NowFromSystemTime();
+    TimeDelta oneYear = TimeDelta::FromDays(365);
+    Time::Exploded exploded;
+
+    Time next_year_time = now + oneYear;
+    next_year_time.LocalExplode(&exploded);
+    next_year_ = exploded.year;
+
+    Time last_year_time = now - oneYear;
+    last_year_time.LocalExplode(&exploded);
+    last_year_ = exploded.year;
+  }
+
+ protected:
+  int next_year_;
+  int last_year_;
 
  private:
   FieldTrialList trial_list_;
@@ -27,20 +43,22 @@ TEST_F(FieldTrialTest, Registration) {
   EXPECT_FALSE(FieldTrialList::Find(name1));
   EXPECT_FALSE(FieldTrialList::Find(name2));
 
-  FieldTrial* trial1 = new FieldTrial(name1, 10);
-  EXPECT_EQ(FieldTrial::kNotParticipating, trial1->group());
+  FieldTrial* trial1 =
+      new FieldTrial(name1, 10, "default name 1 test", next_year_, 12, 31);
+  EXPECT_EQ(FieldTrial::kNotFinalized, trial1->group_);
   EXPECT_EQ(name1, trial1->name());
-  EXPECT_EQ("", trial1->group_name());
+  EXPECT_EQ("", trial1->group_name_internal());
 
   trial1->AppendGroup("", 7);
 
   EXPECT_EQ(trial1, FieldTrialList::Find(name1));
   EXPECT_FALSE(FieldTrialList::Find(name2));
 
-  FieldTrial* trial2 = new FieldTrial(name2, 10);
-  EXPECT_EQ(FieldTrial::kNotParticipating, trial2->group());
+  FieldTrial* trial2 =
+      new FieldTrial(name2, 10, "default name 2 test", next_year_, 12, 31);
+  EXPECT_EQ(FieldTrial::kNotFinalized, trial2->group_);
   EXPECT_EQ(name2, trial2->name());
-  EXPECT_EQ("", trial2->group_name());
+  EXPECT_EQ("", trial2->group_name_internal());
 
   trial2->AppendGroup("a first group", 7);
 
@@ -51,20 +69,28 @@ TEST_F(FieldTrialTest, Registration) {
 
 TEST_F(FieldTrialTest, AbsoluteProbabilities) {
   char always_true[] = " always true";
+  char default_always_true[] = " default always true";
   char always_false[] = " always false";
+  char default_always_false[] = " default always false";
   for (int i = 1; i < 250; ++i) {
     // Try lots of names, by changing the first character of the name.
     always_true[0] = i;
+    default_always_true[0] = i;
     always_false[0] = i;
+    default_always_false[0] = i;
 
-    FieldTrial* trial_true = new FieldTrial(always_true, 10);
+    FieldTrial* trial_true =
+        new FieldTrial(
+            always_true, 10, default_always_true, next_year_, 12, 31);
     const std::string winner = "TheWinner";
     int winner_group = trial_true->AppendGroup(winner, 10);
 
     EXPECT_EQ(winner_group, trial_true->group());
     EXPECT_EQ(winner, trial_true->group_name());
 
-    FieldTrial* trial_false = new FieldTrial(always_false, 10);
+    FieldTrial* trial_false =
+        new FieldTrial(
+            always_false, 10, default_always_false, next_year_, 12, 31);
     int loser_group = trial_false->AppendGroup("ALoser", 0);
 
     EXPECT_NE(loser_group, trial_false->group());
@@ -79,12 +105,13 @@ TEST_F(FieldTrialTest, RemainingProbability) {
   int counter = 0;
   do {
     std::string name = StringPrintf("trial%d", ++counter);
-    trial = new FieldTrial(name, 10);
+    trial = new FieldTrial(name, 10, winner, next_year_, 12, 31);
     trial->AppendGroup(loser, 5);  // 50% chance of not being chosen.
-  } while (trial->group() != FieldTrial::kNotParticipating);
+    // If a group is not assigned, group_ will be kNotFinalized.
+  } while (trial->group_ != FieldTrial::kNotFinalized);
 
-  // Now add a winner with all remaining probability.
-  trial->AppendGroup(winner, FieldTrial::kAllRemainingProbability);
+  // And that 'default' group (winner) should always win.
+  EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());
 
   // And that winner should ALWAYS win.
   EXPECT_EQ(winner, trial->group_name());
@@ -100,14 +127,18 @@ TEST_F(FieldTrialTest, FiftyFiftyProbability) {
   int counter = 0;
   do {
     std::string name = base::StringPrintf("FiftyFifty%d", ++counter);
-    scoped_refptr<FieldTrial> trial(new FieldTrial(name, 2));
+    std::string default_group_name = base::StringPrintf("Default FiftyFifty%d",
+                                                        ++counter);
+    scoped_refptr<FieldTrial> trial(
+        new FieldTrial(name, 2, default_group_name, next_year_, 12, 31));
     trial->AppendGroup("first", 1);  // 50% chance of being chosen.
-    if (trial->group() != FieldTrial::kNotParticipating) {
+    // If group_ is kNotFinalized, then a group assignement hasn't been done.
+    if (trial->group_ != FieldTrial::kNotFinalized) {
       first_winner = true;
       continue;
     }
     trial->AppendGroup("second", 1);  // Always chosen at this point.
-    EXPECT_NE(FieldTrial::kNotParticipating, trial->group());
+    EXPECT_NE(FieldTrial::kNotFinalized, trial->group());
     second_winner = true;
   } while ((!second_winner || !first_winner) && counter < 100);
   EXPECT_TRUE(second_winner);
@@ -116,11 +147,14 @@ TEST_F(FieldTrialTest, FiftyFiftyProbability) {
 
 TEST_F(FieldTrialTest, MiddleProbabilities) {
   char name[] = " same name";
+  char default_group_name[] = " default same name";
   bool false_event_seen = false;
   bool true_event_seen = false;
   for (int i = 1; i < 250; ++i) {
     name[0] = i;
-    FieldTrial* trial = new FieldTrial(name, 10);
+    default_group_name[0] = i;
+    FieldTrial* trial =
+        new FieldTrial(name, 10, default_group_name, next_year_, 12, 31);
     int might_win = trial->AppendGroup("MightWin", 5);
 
     if (trial->group() == might_win) {
@@ -139,16 +173,21 @@ TEST_F(FieldTrialTest, MiddleProbabilities) {
 
 TEST_F(FieldTrialTest, OneWinner) {
   char name[] = "Some name";
+  char default_group_name[] = "Default some name";
   int group_count(10);
 
-  FieldTrial* trial = new FieldTrial(name, group_count);
+  FieldTrial* trial =
+      new FieldTrial(
+          name, group_count, default_group_name, next_year_, 12, 31);
   int winner_index(-2);
   std::string winner_name;
 
   for (int i = 1; i <= group_count; ++i) {
     int might_win = trial->AppendGroup("", 1);
 
-    if (trial->group() == might_win) {
+    // Because we keep appending groups, we want to see if the last group that
+    // was added has been assigned or not.
+    if (trial->group_ == might_win) {
       EXPECT_EQ(-2, winner_index);
       winner_index = might_win;
       StringAppendF(&winner_name, "%d", might_win);
@@ -160,14 +199,34 @@ TEST_F(FieldTrialTest, OneWinner) {
   EXPECT_EQ(trial->group_name(), winner_name);
 }
 
+TEST_F(FieldTrialTest, DisableProbability) {
+  const std::string default_group_name = "Default group";
+  const std::string loser = "Loser";
+  const std::string name = "Trial";
+
+  // Create a field trail that has expired.
+  scoped_refptr<FieldTrial> trial;
+  trial = new FieldTrial(
+      name, 1000000000, default_group_name, last_year_, 1, 1);
+  trial->AppendGroup(loser, 999999999);  // 99.9999999% chance of being chosen.
+
+  // Because trial has expired, we should always be in the default group.
+  EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());
+
+  // And that default_group_name should ALWAYS win.
+  EXPECT_EQ(default_group_name, trial->group_name());
+}
+
 TEST_F(FieldTrialTest, Save) {
   std::string save_string;
 
-  FieldTrial* trial = new FieldTrial("Some name", 10);
+  FieldTrial* trial =
+      new FieldTrial(
+          "Some name", 10, "Default some name", next_year_, 12, 31);
   // There is no winner yet, so no textual group name is associated with trial.
-  EXPECT_EQ("", trial->group_name());
+  EXPECT_EQ("", trial->group_name_internal());
   FieldTrialList::StatesToString(&save_string);
-  EXPECT_EQ("", save_string);
+  EXPECT_EQ("Some name/Default some name/", save_string);
   save_string.clear();
 
   // Create a winning group.
@@ -177,7 +236,8 @@ TEST_F(FieldTrialTest, Save) {
   save_string.clear();
 
   // Create a second trial and winning group.
-  FieldTrial* trial2 = new FieldTrial("xxx", 10);
+  FieldTrial* trial2 =
+      new FieldTrial("xxx", 10, "Default xxx", next_year_, 12, 31);
   trial2->AppendGroup("yyyy", 10);
 
   FieldTrialList::StatesToString(&save_string);
@@ -189,7 +249,7 @@ TEST_F(FieldTrialTest, Restore) {
   EXPECT_TRUE(FieldTrialList::Find("Some_name") == NULL);
   EXPECT_TRUE(FieldTrialList::Find("xxx") == NULL);
 
-  FieldTrialList::StringAugmentsState("Some_name/Winner/xxx/yyyy/");
+  FieldTrialList::CreateTrialsInChildProcess("Some_name/Winner/xxx/yyyy/");
 
   FieldTrial* trial = FieldTrialList::Find("Some_name");
   ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
@@ -203,29 +263,34 @@ TEST_F(FieldTrialTest, Restore) {
 }
 
 TEST_F(FieldTrialTest, BogusRestore) {
-  EXPECT_FALSE(FieldTrialList::StringAugmentsState("MissingSlash"));
-  EXPECT_FALSE(FieldTrialList::StringAugmentsState("MissingGroupName/"));
-  EXPECT_FALSE(FieldTrialList::StringAugmentsState("MissingFinalSlash/gname"));
-  EXPECT_FALSE(FieldTrialList::StringAugmentsState("/noname, only group/"));
+  EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingSlash"));
+  EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingGroupName/"));
+  EXPECT_FALSE(
+      FieldTrialList::CreateTrialsInChildProcess("MissingFinalSlash/gname"));
+  EXPECT_FALSE(
+      FieldTrialList::CreateTrialsInChildProcess("/noname, only group/"));
 }
 
 TEST_F(FieldTrialTest, DuplicateRestore) {
-  FieldTrial* trial = new FieldTrial("Some name", 10);
+  FieldTrial* trial =
+      new FieldTrial(
+          "Some name", 10, "Default some name", next_year_, 12, 31);
   trial->AppendGroup("Winner", 10);
   std::string save_string;
   FieldTrialList::StatesToString(&save_string);
   EXPECT_EQ("Some name/Winner/", save_string);
 
   // It is OK if we redundantly specify a winner.
-  EXPECT_TRUE(FieldTrialList::StringAugmentsState(save_string));
+  EXPECT_TRUE(FieldTrialList::CreateTrialsInChildProcess(save_string));
 
   // But it is an error to try to change to a different winner.
-  EXPECT_FALSE(FieldTrialList::StringAugmentsState("Some name/Loser/"));
+  EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("Some name/Loser/"));
 }
 
 TEST_F(FieldTrialTest, MakeName) {
-  FieldTrial* trial = new FieldTrial("Field Trial", 10);
-  trial->AppendGroup("Winner", 10);
+  FieldTrial* trial =
+      new FieldTrial("Field Trial", 10, "Winner", next_year_, 12, 31);
+  trial->group();
   EXPECT_EQ("Histogram_Winner",
             FieldTrial::MakeName("Histogram", "Field Trial"));
 }