Store field trial parameters in shared memory

base/metrics/field_trial_unittest.cc

Index: base/metrics/field_trial_unittest.cc
diff --git a/base/metrics/field_trial_unittest.cc b/base/metrics/field_trial_unittest.cc
index 890b3e5824e3fb39a586b247377a724b992b8de9..deae3e44ab787c76d0ccf3a2a56872dc20abd6e3 100644
--- a/base/metrics/field_trial_unittest.cc
+++ b/base/metrics/field_trial_unittest.cc
@@ -12,6 +12,7 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
+#include "base/metrics/field_trial_param_associator.h"
 #include "base/rand_util.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
@@ -1230,4 +1231,30 @@ TEST(FieldTrialListTest, DoNotAddSimulatedFieldTrialsToAllocator) {
   ASSERT_EQ(check_string.find("Simulated"), std::string::npos);
 }
 
+TEST(FieldTrialListTest, AssociateFieldTrialParams) {
+  std::string trial_name("Trial1");
+  std::string group_name("Group1");
+
+  // Create a field trial with some params.
+  FieldTrialList field_trial_list(nullptr);
+  FieldTrialList::CreateFieldTrial(trial_name, group_name);
+  std::map<std::string, std::string> params;
+  params["key1"] = "value1";
+  params["key2"] = "value2";
+  FieldTrialParamAssociator::GetInstance()->AssociateFieldTrialParams(
+      trial_name, group_name, params);
+  FieldTrialList::InstantiateFieldTrialAllocatorIfNeeded();
+
+  // Clear all cached params from the associator.
+  FieldTrialParamAssociator::GetInstance()->ClearAllCachedParamsForTesting();
+
+  // Check that we fetch the param from shared memory properly.
+  std::map<std::string, std::string> new_params;
+  FieldTrialParamAssociator::GetInstance()->GetFieldTrialParams(trial_name,
+                                                                &new_params);
+  EXPECT_EQ("value1", new_params["key1"]);
+  EXPECT_EQ("value2", new_params["key2"]);
+  EXPECT_EQ(2U, new_params.size());
+}
+
 }  // namespace base