diff --git a/cros/omaha_request_action.cc b/cros/omaha_request_action.cc
index 0916f9d..51c0ac9 100644
--- a/cros/omaha_request_action.cc
+++ b/cros/omaha_request_action.cc
@@ -763,17 +763,7 @@
   }
 
   // We persist the cohorts sent by omaha even if the status is "noupdate".
-  for (const auto& app : parser_data->apps) {
-    if (app.id == params_->GetAppId()) {
-      if (app.cohort)
-        PersistCohortData(kPrefsOmahaCohort, app.cohort.value());
-      if (app.cohorthint)
-        PersistCohortData(kPrefsOmahaCohortHint, app.cohorthint.value());
-      if (app.cohortname)
-        PersistCohortData(kPrefsOmahaCohortName, app.cohortname.value());
-      break;
-    }
-  }
+  PersistCohorts(*parser_data);
 
   PersistEolInfo(parser_data->updatecheck_attrs);
 
@@ -1398,16 +1388,53 @@
   return true;
 }
 
-bool OmahaRequestAction::PersistCohortData(const string& prefs_key,
-                                           const string& new_value) {
-  if (new_value.empty() && system_state_->prefs()->Exists(prefs_key)) {
-    LOG(INFO) << "Removing stored " << prefs_key << " value.";
-    return system_state_->prefs()->Delete(prefs_key);
-  } else if (!new_value.empty()) {
-    LOG(INFO) << "Storing new setting " << prefs_key << " as " << new_value;
-    return system_state_->prefs()->SetString(prefs_key, new_value);
+void OmahaRequestAction::PersistCohortData(const string& prefs_key,
+                                           const Optional<string>& new_value) {
+  if (!new_value)
+    return;
+  const string& value = new_value.value();
+  if (value.empty() && system_state_->prefs()->Exists(prefs_key)) {
+    if (!system_state_->prefs()->Delete(prefs_key))
+      LOG(ERROR) << "Failed to remove stored " << prefs_key << "value.";
+    else
+      LOG(INFO) << "Removed stored " << prefs_key << " value.";
+  } else if (!value.empty()) {
+    if (!system_state_->prefs()->SetString(prefs_key, value))
+      LOG(INFO) << "Failed to store new setting " << prefs_key << " as "
+                << value;
+    else
+      LOG(INFO) << "Stored cohort setting " << prefs_key << " as " << value;
   }
-  return true;
+}
+
+void OmahaRequestAction::PersistCohorts(const OmahaParserData& parser_data) {
+  for (const auto& app : parser_data.apps) {
+    // For platform App ID.
+    if (app.id == params_->GetAppId()) {
+      PersistCohortData(kPrefsOmahaCohort, app.cohort);
+      PersistCohortData(kPrefsOmahaCohortName, app.cohortname);
+      PersistCohortData(kPrefsOmahaCohortHint, app.cohorthint);
+    } else if (params_->IsDlcAppId(app.id)) {
+      string dlc_id;
+      if (!params_->GetDlcId(app.id, &dlc_id)) {
+        LOG(WARNING) << "Skip persisting cohorts for DLC App ID=" << app.id
+                     << " as it is not in the request params.";
+        continue;
+      }
+      PrefsInterface* prefs = system_state_->prefs();
+      PersistCohortData(
+          prefs->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohort}),
+          app.cohort);
+      PersistCohortData(
+          prefs->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohortName}),
+          app.cohortname);
+      PersistCohortData(
+          prefs->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohortHint}),
+          app.cohorthint);
+    } else {
+      LOG(WARNING) << "Skip persisting cohorts for unknown App ID=" << app.id;
+    }
+  }
 }
 
 bool OmahaRequestAction::PersistEolInfo(const map<string, string>& attrs) {
diff --git a/cros/omaha_request_action.h b/cros/omaha_request_action.h
index 1a3a912..9576a05 100644
--- a/cros/omaha_request_action.h
+++ b/cros/omaha_request_action.h
@@ -28,6 +28,7 @@
 
 #include <gtest/gtest_prod.h>  // for FRIEND_TEST
 
+#include <base/optional.h>
 #include <brillo/secure_blob.h>
 #include <curl/curl.h>
 
@@ -176,12 +177,17 @@
                                  int install_date_days,
                                  InstallDateProvisioningSource source);
 
-  // Persist the new cohort* value received in the XML file in the |prefs_key|
-  // preference file. If the |new_value| is empty, the currently stored value
-  // will be deleted. Don't call this function with an empty |new_value| if the
-  // value was not set in the XML, since that would delete the stored value.
-  bool PersistCohortData(const std::string& prefs_key,
-                         const std::string& new_value);
+  // Persist the new cohort value received in the XML file in the |prefs_key|
+  // preference file. If the |new_value| is empty, do nothing. If the
+  // |new_value| stores and empty value, the currently stored value will be
+  // deleted. Don't call this function with an empty |new_value| if the value
+  // was not set in the XML, since that would delete the stored value.
+  void PersistCohortData(const std::string& prefs_key,
+                         const base::Optional<std::string>& new_value);
+
+  // Parses and persists the cohorts sent back in the updatecheck tag
+  // attributes.
+  void PersistCohorts(const OmahaParserData& parser_data);
 
   // Parses and persists the end-of-life date flag sent back in the updatecheck
   // tag attributes. The flags will be validated and stored in the Prefs.
diff --git a/cros/omaha_request_action_unittest.cc b/cros/omaha_request_action_unittest.cc
index c3842b8..8d94195 100644
--- a/cros/omaha_request_action_unittest.cc
+++ b/cros/omaha_request_action_unittest.cc
@@ -204,7 +204,13 @@
                 : "") +
            (dlc_app_update
                 ? "<app appid=\"" + request_params.GetDlcAppId(kDlcId1) +
-                      "\" status=\"ok\">"
+                      "\" " +
+                      (include_dlc_cohorts
+                           ? "cohort=\"" + dlc_cohort + "\" cohorthint=\"" +
+                                 dlc_cohorthint + "\" cohortname=\"" +
+                                 dlc_cohortname + "\" "
+                           : "") +
+                      "status=\"ok\">"
                       "<updatecheck status=\"ok\"><urls><url codebase=\"" +
                       codebase + "\"/><url codebase=\"" + codebase2 +
                       "\"/></urls><manifest version=\"" + version +
@@ -216,7 +222,13 @@
                 : "") +
            (dlc_app_no_update
                 ? "<app appid=\"" + request_params.GetDlcAppId(kDlcId2) +
-                      "\"><updatecheck status=\"noupdate\"/></app>"
+                      +"\" " +
+                      (include_dlc_cohorts
+                           ? "cohort=\"" + dlc_cohort + "\" cohorthint=\"" +
+                                 dlc_cohorthint + "\" cohortname=\"" +
+                                 dlc_cohortname + "\" "
+                           : "") +
+                      "><updatecheck status=\"noupdate\"/></app>"
                 : "") +
            "</response>";
   }
@@ -252,6 +264,11 @@
   string cohort = "";
   string cohorthint = "";
   string cohortname = "";
+  // Whether to include Omaha cohorts for DLC apps.
+  bool include_dlc_cohorts = false;
+  string dlc_cohort = "";
+  string dlc_cohorthint = "";
+  string dlc_cohortname = "";
 
   // Whether to include the CrOS <!ENTITY> in the XML response.
   bool include_entity = false;
@@ -1240,8 +1257,16 @@
   fake_update_response_.cohort = "s/154454/8479665";
   fake_update_response_.cohorthint = "please-put-me-on-beta";
   fake_update_response_.cohortname = "stable";
+  request_params_.set_dlc_apps_params(
+      {{request_params_.GetDlcAppId(kDlcId1), {.name = kDlcId1}}});
+  fake_update_response_.dlc_app_update = true;
+  fake_update_response_.include_dlc_cohorts = true;
+  fake_update_response_.dlc_cohort = "s/154454/8479665/dlc";
+  fake_update_response_.dlc_cohorthint = "please-put-me-on-beta-dlc";
+  fake_update_response_.dlc_cohortname = "stable-dlc";
   tuc_params_.http_response = fake_update_response_.GetUpdateResponse();
 
+  EXPECT_CALL(mock_excluder_, IsExcluded(_)).WillRepeatedly(Return(false));
   ASSERT_TRUE(TestUpdateCheck());
 
   string value;
@@ -1253,18 +1278,52 @@
 
   EXPECT_TRUE(fake_prefs_.GetString(kPrefsOmahaCohortName, &value));
   EXPECT_EQ(fake_update_response_.cohortname, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey({kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohort}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohort, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortHint}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohorthint, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortName}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohortname, value);
 }
 
 TEST_F(OmahaRequestActionTest, CohortsAreUpdated) {
   EXPECT_TRUE(fake_prefs_.SetString(kPrefsOmahaCohort, "old_value"));
   EXPECT_TRUE(fake_prefs_.SetString(kPrefsOmahaCohortHint, "old_hint"));
   EXPECT_TRUE(fake_prefs_.SetString(kPrefsOmahaCohortName, "old_name"));
+  const string dlc_cohort_key =
+      fake_prefs_.CreateSubKey({kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohort});
+  const string dlc_cohort_hint_key = fake_prefs_.CreateSubKey(
+      {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortHint});
+  const string dlc_cohort_name_key = fake_prefs_.CreateSubKey(
+      {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortName});
+  request_params_.set_dlc_apps_params(
+      {{request_params_.GetDlcAppId(kDlcId1), {.name = kDlcId1}}});
+  EXPECT_TRUE(fake_prefs_.SetString(dlc_cohort_key, "old_value_dlc"));
+  EXPECT_TRUE(fake_prefs_.SetString(dlc_cohort_hint_key, "old_hint_dlc"));
+  EXPECT_TRUE(fake_prefs_.SetString(dlc_cohort_name_key, "old_name_dlc"));
   fake_update_response_.include_cohorts = true;
   fake_update_response_.cohort = "s/154454/8479665";
   fake_update_response_.cohorthint = "please-put-me-on-beta";
   fake_update_response_.cohortname = "";
+  fake_update_response_.dlc_app_update = true;
+  fake_update_response_.include_dlc_cohorts = true;
+  fake_update_response_.dlc_cohort = "s/154454/8479665/dlc";
+  fake_update_response_.dlc_cohorthint = "please-put-me-on-beta-dlc";
+  fake_update_response_.dlc_cohortname = "";
   tuc_params_.http_response = fake_update_response_.GetUpdateResponse();
 
+  EXPECT_CALL(mock_excluder_, IsExcluded(_)).WillRepeatedly(Return(false));
   ASSERT_TRUE(TestUpdateCheck());
 
   string value;
@@ -1275,12 +1334,23 @@
   EXPECT_EQ(fake_update_response_.cohorthint, value);
 
   EXPECT_FALSE(fake_prefs_.GetString(kPrefsOmahaCohortName, &value));
+
+  EXPECT_TRUE(fake_prefs_.GetString(dlc_cohort_key, &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohort, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(dlc_cohort_hint_key, &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohorthint, value);
+
+  EXPECT_FALSE(fake_prefs_.GetString(dlc_cohort_name_key, &value));
 }
 
 TEST_F(OmahaRequestActionTest, CohortsAreNotModifiedWhenMissing) {
   tuc_params_.http_response = fake_update_response_.GetUpdateResponse();
 
   EXPECT_TRUE(fake_prefs_.SetString(kPrefsOmahaCohort, "old_value"));
+  const string dlc_cohort_key =
+      fake_prefs_.CreateSubKey({kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohort});
+  EXPECT_TRUE(fake_prefs_.SetString(dlc_cohort_key, "old_value_dlc"));
   ASSERT_TRUE(TestUpdateCheck());
 
   string value;
@@ -1289,6 +1359,18 @@
 
   EXPECT_FALSE(fake_prefs_.GetString(kPrefsOmahaCohortHint, &value));
   EXPECT_FALSE(fake_prefs_.GetString(kPrefsOmahaCohortName, &value));
+
+  EXPECT_TRUE(fake_prefs_.GetString(dlc_cohort_key, &value));
+  EXPECT_EQ("old_value_dlc", value);
+
+  EXPECT_FALSE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortHint}),
+      &value));
+  EXPECT_FALSE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortName}),
+      &value));
 }
 
 TEST_F(OmahaRequestActionTest, CohortsArePersistedWhenNoUpdate) {
@@ -1319,8 +1401,18 @@
   fake_update_response_.cohort = "s/154454/8479665";
   fake_update_response_.cohorthint = "please-put-me-on-beta";
   fake_update_response_.cohortname = "stable";
+  request_params_.set_dlc_apps_params(
+      {{request_params_.GetDlcAppId(kDlcId1), {.name = kDlcId1}},
+       {request_params_.GetDlcAppId(kDlcId2), {.name = kDlcId2}}});
+  fake_update_response_.dlc_app_update = true;
+  fake_update_response_.dlc_app_no_update = true;
+  fake_update_response_.include_dlc_cohorts = true;
+  fake_update_response_.dlc_cohort = "s/154454/8479665/dlc";
+  fake_update_response_.dlc_cohorthint = "please-put-me-on-beta-dlc";
+  fake_update_response_.dlc_cohortname = "stable-dlc";
   tuc_params_.http_response = fake_update_response_.GetUpdateResponse();
 
+  EXPECT_CALL(mock_excluder_, IsExcluded(_)).WillRepeatedly(Return(false));
   ASSERT_TRUE(TestUpdateCheck());
 
   string value;
@@ -1332,6 +1424,37 @@
 
   EXPECT_TRUE(fake_prefs_.GetString(kPrefsOmahaCohortName, &value));
   EXPECT_EQ(fake_update_response_.cohortname, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey({kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohort}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohort, value);
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey({kDlcPrefsSubDir, kDlcId2, kPrefsOmahaCohort}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohort, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortHint}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohorthint, value);
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId2, kPrefsOmahaCohortHint}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohorthint, value);
+
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId1, kPrefsOmahaCohortName}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohortname, value);
+  EXPECT_TRUE(fake_prefs_.GetString(
+      fake_prefs_.CreateSubKey(
+          {kDlcPrefsSubDir, kDlcId2, kPrefsOmahaCohortName}),
+      &value));
+  EXPECT_EQ(fake_update_response_.dlc_cohortname, value);
 }
 
 TEST_F(OmahaRequestActionTest, NoOutputPipeTest) {
diff --git a/cros/omaha_request_builder_xml.cc b/cros/omaha_request_builder_xml.cc
index 43ee548..739abbf 100644
--- a/cros/omaha_request_builder_xml.cc
+++ b/cros/omaha_request_builder_xml.cc
@@ -215,9 +215,10 @@
   return app_body;
 }
 
-string OmahaRequestBuilderXml::GetCohortArg(const string arg_name,
-                                            const string prefs_key,
-                                            const string override_value) const {
+string OmahaRequestBuilderXml::GetCohortArg(
+    const string& arg_name,
+    const string& prefs_key,
+    const string& override_value) const {
   string cohort_value;
   if (!override_value.empty()) {
     // |override_value| take precedence over pref value.
@@ -296,14 +297,30 @@
   }
 
   string app_cohort_args;
-  app_cohort_args += GetCohortArg("cohort", kPrefsOmahaCohort);
-  app_cohort_args += GetCohortArg("cohortname", kPrefsOmahaCohortName);
+  string cohort_key = kPrefsOmahaCohort;
+  string cohortname_key = kPrefsOmahaCohortName;
+  string cohorthint_key = kPrefsOmahaCohortHint;
 
+  // Override the cohort keys for DLC App IDs.
+  const auto& dlc_apps_params = params_->dlc_apps_params();
+  auto itr = dlc_apps_params.find(app_data.id);
+  if (itr != dlc_apps_params.end()) {
+    auto dlc_id = itr->second.name;
+    cohort_key =
+        prefs_->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohort});
+    cohortname_key =
+        prefs_->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohortName});
+    cohorthint_key =
+        prefs_->CreateSubKey({kDlcPrefsSubDir, dlc_id, kPrefsOmahaCohortHint});
+  }
+
+  app_cohort_args += GetCohortArg("cohort", cohort_key);
+  app_cohort_args += GetCohortArg("cohortname", cohortname_key);
   // Policy provided value overrides pref.
-  string autoupdate_token = params_->autoupdate_token();
-  app_cohort_args += GetCohortArg("cohorthint",
-                                  kPrefsOmahaCohortHint,
-                                  autoupdate_token /* override_value */);
+  app_cohort_args +=
+      GetCohortArg("cohorthint",
+                   cohorthint_key,
+                   params_->autoupdate_token() /* override_value */);
 
   string fingerprint_arg;
   if (!params_->os_build_fingerprint().empty()) {
diff --git a/cros/omaha_request_builder_xml.h b/cros/omaha_request_builder_xml.h
index 4f860dd..0aca7f3 100644
--- a/cros/omaha_request_builder_xml.h
+++ b/cros/omaha_request_builder_xml.h
@@ -168,9 +168,9 @@
   // Returns the cohort* argument to include in the <app> tag for the passed
   // |arg_name| and |prefs_key|, if any. The return value is suitable to
   // concatenate to the list of arguments and includes a space at the end.
-  std::string GetCohortArg(const std::string arg_name,
-                           const std::string prefs_key,
-                           const std::string override_value = "") const;
+  std::string GetCohortArg(const std::string& arg_name,
+                           const std::string& prefs_key,
+                           const std::string& override_value = "") const;
 
   // Returns an XML ping element if any of the elapsed days need to be
   // sent, or an empty string otherwise.
diff --git a/cros/omaha_request_builder_xml_unittest.cc b/cros/omaha_request_builder_xml_unittest.cc
index 055d0f3..c04c994 100644
--- a/cros/omaha_request_builder_xml_unittest.cc
+++ b/cros/omaha_request_builder_xml_unittest.cc
@@ -21,13 +21,19 @@
 #include <vector>
 
 #include <base/guid.h>
+#include <base/strings/stringprintf.h>
 #include <gtest/gtest.h>
 
+#include "update_engine/common/fake_prefs.h"
 #include "update_engine/cros/fake_system_state.h"
 
 using std::pair;
 using std::string;
 using std::vector;
+using testing::_;
+using testing::DoAll;
+using testing::Return;
+using testing::SetArgPointee;
 
 namespace chromeos_update_engine {
 
@@ -398,4 +404,74 @@
           "<event eventtype=\"3\" eventresult=\"0\" errorcode=\"62\"></event>"))
       << request_xml;
 }
+
+TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlDlcCohortMissingCheck) {
+  OmahaRequestParams omaha_request_params{&fake_system_state_};
+  constexpr char kDlcId[] = "test-dlc-id";
+  omaha_request_params.set_dlc_apps_params(
+      {{omaha_request_params.GetDlcAppId(kDlcId), {.name = kDlcId}}});
+  auto* mock_prefs = fake_system_state_.mock_prefs();
+  OmahaEvent event(OmahaEvent::kTypeUpdateDownloadStarted);
+  OmahaRequestBuilderXml omaha_request{
+      &event, &omaha_request_params, false, false, 0, 0, 0, mock_prefs, ""};
+  // OS App ID Expectations.
+  EXPECT_CALL(*mock_prefs, Exists(kPrefsOmahaCohort));
+  EXPECT_CALL(*mock_prefs, Exists(kPrefsOmahaCohortName));
+  EXPECT_CALL(*mock_prefs, Exists(kPrefsOmahaCohortHint));
+  // DLC App ID Expectations.
+  EXPECT_CALL(*mock_prefs,
+              Exists(PrefsInterface::CreateSubKey(
+                  {kDlcPrefsSubDir, kDlcId, kPrefsOmahaCohort})));
+  EXPECT_CALL(*mock_prefs,
+              Exists(PrefsInterface::CreateSubKey(
+                  {kDlcPrefsSubDir, kDlcId, kPrefsOmahaCohortName})));
+  EXPECT_CALL(*mock_prefs,
+              Exists(PrefsInterface::CreateSubKey(
+                  {kDlcPrefsSubDir, kDlcId, kPrefsOmahaCohortHint})));
+  const string request_xml = omaha_request.GetRequest();
+
+  // Check that no cohorts are in the request.
+  EXPECT_EQ(0, CountSubstringInString(request_xml, "cohort=")) << request_xml;
+  EXPECT_EQ(0, CountSubstringInString(request_xml, "cohortname="))
+      << request_xml;
+  EXPECT_EQ(0, CountSubstringInString(request_xml, "cohorthint="))
+      << request_xml;
+}
+
+TEST_F(OmahaRequestBuilderXmlTest, GetRequestXmlDlcCohortCheck) {
+  OmahaRequestParams omaha_request_params{&fake_system_state_};
+  const string kDlcId = "test-dlc-id";
+  omaha_request_params.set_dlc_apps_params(
+      {{omaha_request_params.GetDlcAppId(kDlcId), {.name = kDlcId}}});
+  FakePrefs fake_prefs;
+  fake_system_state_.set_prefs(&fake_prefs);
+  OmahaEvent event(OmahaEvent::kTypeUpdateDownloadStarted);
+  OmahaRequestBuilderXml omaha_request{
+      &event, &omaha_request_params, false, false, 0, 0, 0, &fake_prefs, ""};
+  // DLC App ID Expectations.
+  const string dlc_cohort_key = PrefsInterface::CreateSubKey(
+      {kDlcPrefsSubDir, kDlcId, kPrefsOmahaCohort});
+  const string kDlcCohortVal = "test-cohort";
+  EXPECT_TRUE(fake_prefs.SetString(dlc_cohort_key, kDlcCohortVal));
+  const string dlc_cohort_name_key = PrefsInterface::CreateSubKey(
+      {kDlcPrefsSubDir, kDlcId, kPrefsOmahaCohortName});
+  const string kDlcCohortNameVal = "test-cohortname";
+  EXPECT_TRUE(fake_prefs.SetString(dlc_cohort_name_key, kDlcCohortNameVal));
+  const string dlc_cohort_hint_key = PrefsInterface::CreateSubKey(
+      {kDlcPrefsSubDir, kDlcId, kPrefsOmahaCohortHint});
+  const string kDlcCohortHintVal = "test-cohortval";
+  EXPECT_TRUE(fake_prefs.SetString(dlc_cohort_hint_key, kDlcCohortHintVal));
+  const string request_xml = omaha_request.GetRequest();
+
+  EXPECT_EQ(1,
+            CountSubstringInString(
+                request_xml,
+                base::StringPrintf(
+                    "cohort=\"%s\" cohortname=\"%s\" cohorthint=\"%s\"",
+                    kDlcCohortVal.c_str(),
+                    kDlcCohortNameVal.c_str(),
+                    kDlcCohortHintVal.c_str())))
+      << request_xml;
+}
+
 }  // namespace chromeos_update_engine
diff --git a/cros/omaha_request_params.cc b/cros/omaha_request_params.cc
index c814e00..e7e719b 100644
--- a/cros/omaha_request_params.cc
+++ b/cros/omaha_request_params.cc
@@ -274,6 +274,14 @@
   return dlc_apps_params().find(app_id) != dlc_apps_params().end();
 }
 
+bool OmahaRequestParams::GetDlcId(const string& app_id, string* dlc_id) const {
+  auto itr = dlc_apps_params_.find(app_id);
+  if (itr == dlc_apps_params_.end())
+    return false;
+  *dlc_id = itr->second.name;
+  return true;
+}
+
 void OmahaRequestParams::SetDlcNoUpdate(const string& app_id) {
   auto itr = dlc_apps_params_.find(app_id);
   if (itr == dlc_apps_params_.end())
diff --git a/cros/omaha_request_params.h b/cros/omaha_request_params.h
index 26ea1c9..fa452ce 100644
--- a/cros/omaha_request_params.h
+++ b/cros/omaha_request_params.h
@@ -228,6 +228,10 @@
   // request parameters.
   virtual bool IsDlcAppId(const std::string& app_id) const;
 
+  // Returns the DLC App ID if the given App ID is a DLC that is currently part
+  // of the request parameters.
+  virtual bool GetDlcId(const std::string& app_id, std::string* dlc_id) const;
+
   // If the App ID is a DLC App ID will set to no update.
   void SetDlcNoUpdate(const std::string& app_id);
 
diff --git a/cros/omaha_request_params_unittest.cc b/cros/omaha_request_params_unittest.cc
index 71f3d4c..ff52fc2 100644
--- a/cros/omaha_request_params_unittest.cc
+++ b/cros/omaha_request_params_unittest.cc
@@ -261,4 +261,33 @@
   EXPECT_TRUE(params_.Init("", "", {}));
   EXPECT_EQ("fake_requisition", params_.device_requisition());
 }
+
+TEST_F(OmahaRequestParamsTest, GetMissingDlcId) {
+  EXPECT_TRUE(params_.Init("", "", {}));
+
+  string dlc_id;
+  EXPECT_FALSE(params_.GetDlcId("some-dlc-app-id", &dlc_id));
+}
+
+TEST_F(OmahaRequestParamsTest, GetDlcId) {
+  EXPECT_TRUE(params_.Init("", "", {}));
+  const string kExpectedDlcId = "test-dlc";
+  const string dlc_app_id = params_.GetDlcAppId(kExpectedDlcId);
+  params_.set_dlc_apps_params({{dlc_app_id, {.name = kExpectedDlcId}}});
+
+  string dlc_id;
+  EXPECT_TRUE(params_.GetDlcId(dlc_app_id, &dlc_id));
+  EXPECT_EQ(kExpectedDlcId, dlc_id);
+}
+
+TEST_F(OmahaRequestParamsTest, GetDlcAppId) {
+  EXPECT_TRUE(params_.Init("", "", {}));
+  const string kAppId = "test-app-id";
+  params_.set_app_id(kAppId);
+  const string kDlcId = "test-dlc";
+  const string expected_dlc_app_id = kAppId + "_" + kDlcId;
+
+  EXPECT_EQ(expected_dlc_app_id, params_.GetDlcAppId(kDlcId));
+}
+
 }  // namespace chromeos_update_engine