Update from https://crrev.com/312398

base/metrics/field_trial.cc

Index: base/metrics/field_trial.cc
diff --git a/base/metrics/field_trial.cc b/base/metrics/field_trial.cc
index 7efca7a3ef53cdaa8093b880b44d7e469bebc27d..e03c94c5969950bc7a82122b2f7602d540aeccb8 100644
--- a/base/metrics/field_trial.cc
+++ b/base/metrics/field_trial.cc
@@ -223,6 +223,20 @@ bool FieldTrial::GetActiveGroup(ActiveGroup* active_group) const {
   return true;
 }
 
+bool FieldTrial::GetState(FieldTrialState* field_trial_state) const {
+  if (!enable_field_trial_)
+    return false;
+  field_trial_state->trial_name = trial_name_;
+  // If the group name is empty (hasn't been finalized yet), use the default
+  // group name instead.
+  if (!group_name_.empty())
+    field_trial_state->group_name = group_name_;
+  else
+    field_trial_state->group_name = default_group_name_;
+  field_trial_state->activated = group_reported_;
+  return true;
+}
+
 //------------------------------------------------------------------------------
 // FieldTrialList methods and members.
 
@@ -387,6 +401,29 @@ void FieldTrialList::StatesToString(std::string* output) {
 }
 
 // static
+void FieldTrialList::AllStatesToString(std::string* output) {
+  if (!global_)
+    return;
+  AutoLock auto_lock(global_->lock_);
+
+  for (const auto& registered : global_->registered_) {
+    FieldTrial::FieldTrialState trial;
+    if (!registered.second->GetState(&trial))
+      continue;
+    DCHECK_EQ(std::string::npos,
+              trial.trial_name.find(kPersistentStringSeparator));
+    DCHECK_EQ(std::string::npos,
+              trial.group_name.find(kPersistentStringSeparator));
+    if (trial.activated)
+      output->append(1, kActivationMarker);
+    output->append(trial.trial_name);
+    output->append(1, kPersistentStringSeparator);
+    output->append(trial.group_name);
+    output->append(1, kPersistentStringSeparator);
+  }
+}
+
+// static
 void FieldTrialList::GetActiveFieldTrialGroups(
     FieldTrial::ActiveGroups* active_groups) {
   DCHECK(active_groups->empty());