Send all field trials from the browser.

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..a1ba5172857e20310481f5b1e0c6cf75d6d3beb2 100644
--- a/base/metrics/field_trial.cc
+++ b/base/metrics/field_trial.cc
@@ -223,6 +223,15 @@ bool FieldTrial::GetActiveGroup(ActiveGroup* active_group) const {
   return true;
 }
 
+bool FieldTrial::GetFieldTrialState(FieldTrialState* field_trial_state) const {
+  if (!enable_field_trial_)
+    return false;
+  field_trial_state->trial_name = trial_name_;
+  field_trial_state->group_name = group_name_;
+  field_trial_state->activated = group_reported_;
+  return true;
+}
+
 //------------------------------------------------------------------------------
 // FieldTrialList methods and members.
 
@@ -387,6 +396,24 @@ void FieldTrialList::StatesToString(std::string* output) {
 }
 
 // static
+void FieldTrialList::AllStatesToString(std::string* output) {
+  FieldTrial::AllGroups all_groups;
+  GetAllFieldTrialGroups(&all_groups);
+  for (const FieldTrial::FieldTrialState& trial : all_groups) {
+    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());
@@ -403,6 +430,21 @@ void FieldTrialList::GetActiveFieldTrialGroups(
 }
 
 // static
+void FieldTrialList::GetAllFieldTrialGroups(

[Alexei Svitkine (slow), 2014/11/05 22:50:53]

Hmm, actually if this method is private, I suggest not to have it at all and
just inline this into the AllStatesToString() implementation. i.e. that function
can iterate directly over global_->registered_.

[Georges Khalil, 2014/11/06 18:36:28]

Done.

+    FieldTrial::AllGroups* all_groups) {
+  DCHECK(all_groups->empty());
+  if (!global_)
+    return;
+  AutoLock auto_lock(global_->lock_);
+
+  for (const auto& it : global_->registered_) {

[Alexei Svitkine (slow), 2014/11/05 22:50:53]

Nit: I prefer to explicitly name the type for clarity and name it something
other than it, e.g.:

 for (const FieldTrial& trial : global_->registered_) {

[Georges Khalil, 2014/11/06 18:36:28]

Type is std::pair<string, base::FieldTrial *> and caused indentation issue,
hence the use of auto.

+    FieldTrial::FieldTrialState field_trial_state;
+    if (it.second->GetFieldTrialState(&field_trial_state))
+      all_groups->push_back(field_trial_state);
+  }
+}
+
+// static
 bool FieldTrialList::CreateTrialsFromString(
     const std::string& trials_string,
     FieldTrialActivationMode mode,