Add support for GCM subtypes to desktop Instance ID implementation

components/gcm_driver/gcm_client_impl_unittest.cc

Index: components/gcm_driver/gcm_client_impl_unittest.cc
diff --git a/components/gcm_driver/gcm_client_impl_unittest.cc b/components/gcm_driver/gcm_client_impl_unittest.cc
index 0368e7648539f327d37c0c8566ee9d7dd66bcc75..86599e2392de7158acf25229cef5c4f8bb044800 100644
--- a/components/gcm_driver/gcm_client_impl_unittest.cc
+++ b/components/gcm_driver/gcm_client_impl_unittest.cc
@@ -6,6 +6,7 @@
 
 #include <stdint.h>
 
+#include <initializer_list>
 #include <memory>
 
 #include "base/command_line.h"
@@ -29,9 +30,12 @@
 #include "google_apis/gcm/protocol/android_checkin.pb.h"
 #include "google_apis/gcm/protocol/checkin.pb.h"
 #include "google_apis/gcm/protocol/mcs.pb.h"
+#include "net/test/gtest_util.h"
+#include "net/test/scoped_disable_exit_on_dfatal.h"
 #include "net/url_request/test_url_fetcher_factory.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest-spi.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace gcm {
@@ -55,6 +59,7 @@ const uint64_t kDeviceSecurityToken = 12345;
 const uint64_t kDeviceAndroidId2 = 11111;
 const uint64_t kDeviceSecurityToken2 = 2222;
 const int64_t kSettingsCheckinInterval = 16 * 60 * 60;
+const char kCategoryForSubtypes[] = "com.chrome.stable:macosx";
 const char kAppId[] = "app_id";
 const char kSender[] = "project_id";
 const char kSender2[] = "project_id2";
@@ -70,12 +75,13 @@ const char kDeleteTokenResponse[] = "token=foo";
 // Helper for building arbitrary data messages.
 MCSMessage BuildDownstreamMessage(
     const std::string& project_id,
-    const std::string& app_id,
+    const std::string& category,
+    const std::string& subtype,
     const std::map<std::string, std::string>& data,
     const std::string& raw_data) {
   mcs_proto::DataMessageStanza data_message;
   data_message.set_from(project_id);
-  data_message.set_category(app_id);
+  data_message.set_category(category);
   for (std::map<std::string, std::string>::const_iterator iter = data.begin();
        iter != data.end();
        ++iter) {
@@ -83,6 +89,11 @@ MCSMessage BuildDownstreamMessage(
     app_data->set_key(iter->first);
     app_data->set_value(iter->second);
   }
+  if (!subtype.empty()) {
+    mcs_proto::AppData* app_data = data_message.add_app_data();
+    app_data->set_key("subtype");
+    app_data->set_value(subtype);
+  }
   data_message.set_raw_data(raw_data);
   return MCSMessage(kDataMessageStanzaTag, data_message);
 }
@@ -531,6 +542,7 @@ void GCMClientImplTest::InitializeGCMClient() {
   // Actual initialization.
   GCMClient::ChromeBuildInfo chrome_build_info;
   chrome_build_info.version = kChromeVersion;
+  chrome_build_info.category_for_subtypes = kCategoryForSubtypes;
   gcm_client_->Initialize(chrome_build_info, gcm_store_path(), task_runner_,
                           url_request_context_getter_,
                           base::WrapUnique<Encryptor>(new FakeEncryptor), this);
@@ -818,8 +830,9 @@ TEST_F(GCMClientImplTest, DispatchDownstreamMessage) {
   expected_data["key2"] = "value2";
 
   // Message for kSender will be received.
-  MCSMessage message(BuildDownstreamMessage(kSender, kAppId, expected_data,
-                                            std::string() /* raw_data */));
+  MCSMessage message(
+      BuildDownstreamMessage(kSender, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
   EXPECT_TRUE(message.IsValid());
   ReceiveMessageFromMCS(message);
 
@@ -833,8 +846,9 @@ TEST_F(GCMClientImplTest, DispatchDownstreamMessage) {
   reset_last_event();
 
   // Message for kSender2 will be received.
-  MCSMessage message2(BuildDownstreamMessage(kSender2, kAppId, expected_data,
-                                             std::string() /* raw_data */));
+  MCSMessage message2(
+      BuildDownstreamMessage(kSender2, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
   EXPECT_TRUE(message2.IsValid());
   ReceiveMessageFromMCS(message2);
 
@@ -847,8 +861,9 @@ TEST_F(GCMClientImplTest, DispatchDownstreamMessage) {
   reset_last_event();
 
   // Message from kSender3 will be dropped.
-  MCSMessage message3(BuildDownstreamMessage(kSender3, kAppId, expected_data,
-                                             std::string() /* raw_data */));
+  MCSMessage message3(
+      BuildDownstreamMessage(kSender3, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
   EXPECT_TRUE(message3.IsValid());
   ReceiveMessageFromMCS(message3);
 
@@ -862,8 +877,8 @@ TEST_F(GCMClientImplTest, DispatchDownstreamMessageRawData) {
 
   std::map<std::string, std::string> expected_data;
 
-  MCSMessage message(BuildDownstreamMessage(kSender, kAppId, expected_data,
-                                            kRawData));
+  MCSMessage message(BuildDownstreamMessage(
+      kSender, kAppId, std::string() /* subtype */, expected_data, kRawData));
   EXPECT_TRUE(message.IsValid());
   ReceiveMessageFromMCS(message);
 
@@ -879,8 +894,9 @@ TEST_F(GCMClientImplTest, DispatchDownstreamMessageSendError) {
   expected_data["message_type"] = "send_error";
   expected_data["google.message_id"] = "007";
   expected_data["error_details"] = "some details";
-  MCSMessage message(BuildDownstreamMessage(kSender, kAppId, expected_data,
-                                            std::string() /* raw_data */));
+  MCSMessage message(
+      BuildDownstreamMessage(kSender, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
   EXPECT_TRUE(message.IsValid());
   ReceiveMessageFromMCS(message);
 
@@ -897,8 +913,9 @@ TEST_F(GCMClientImplTest, DispatchDownstreamMessageSendError) {
 TEST_F(GCMClientImplTest, DispatchDownstreamMessgaesDeleted) {
   std::map<std::string, std::string> expected_data;
   expected_data["message_type"] = "deleted_messages";
-  MCSMessage message(BuildDownstreamMessage(kSender, kAppId, expected_data,
-                                            std::string() /* raw_data */));
+  MCSMessage message(
+      BuildDownstreamMessage(kSender, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
   EXPECT_TRUE(message.IsValid());
   ReceiveMessageFromMCS(message);
 
@@ -1392,13 +1409,16 @@ class GCMClientInstanceIDTest : public GCMClientImplTest {
                      const std::string& instance_id);
   void RemoveInstanceID(const std::string& app_id);
   void GetToken(const std::string& app_id,
+                bool use_subtype,
                 const std::string& authorized_entity,
                 const std::string& scope);
   void DeleteToken(const std::string& app_id,
+                   bool use_subtype,
                    const std::string& authorized_entity,
                    const std::string& scope);
   void CompleteDeleteToken();
   bool ExistsToken(const std::string& app_id,
+                   bool use_subtype,
                    const std::string& authorized_entity,
                    const std::string& scope) const;
 };
@@ -1419,11 +1439,13 @@ void GCMClientInstanceIDTest::RemoveInstanceID(const std::string& app_id) {
 }
 
 void GCMClientInstanceIDTest::GetToken(const std::string& app_id,
+                                       bool use_subtype,
                                        const std::string& authorized_entity,
                                        const std::string& scope) {
   std::unique_ptr<InstanceIDTokenInfo> instance_id_info(
       new InstanceIDTokenInfo);
   instance_id_info->app_id = app_id;
+  instance_id_info->use_subtype = use_subtype;
   instance_id_info->authorized_entity = authorized_entity;
   instance_id_info->scope = scope;
   gcm_client()->Register(
@@ -1431,11 +1453,13 @@ void GCMClientInstanceIDTest::GetToken(const std::string& app_id,
 }
 
 void GCMClientInstanceIDTest::DeleteToken(const std::string& app_id,
+                                          bool use_subtype,
                                           const std::string& authorized_entity,
                                           const std::string& scope) {
   std::unique_ptr<InstanceIDTokenInfo> instance_id_info(
       new InstanceIDTokenInfo);
   instance_id_info->app_id = app_id;
+  instance_id_info->use_subtype = use_subtype;
   instance_id_info->authorized_entity = authorized_entity;
   instance_id_info->scope = scope;
   gcm_client()->Unregister(
@@ -1454,50 +1478,98 @@ void GCMClientInstanceIDTest::CompleteDeleteToken() {
 }
 
 bool GCMClientInstanceIDTest::ExistsToken(const std::string& app_id,
+                                          bool use_subtype,
                                           const std::string& authorized_entity,
                                           const std::string& scope) const {
   std::unique_ptr<InstanceIDTokenInfo> instance_id_info(
       new InstanceIDTokenInfo);
   instance_id_info->app_id = app_id;
+  instance_id_info->use_subtype = use_subtype;
   instance_id_info->authorized_entity = authorized_entity;
   instance_id_info->scope = scope;
-  return gcm_client()->registrations_.count(
-      make_linked_ptr<RegistrationInfo>(instance_id_info.release())) > 0;
+  RegistrationInfoMap::const_iterator registrations_iter =
+      gcm_client()->registrations_.find(
+          make_linked_ptr<RegistrationInfo>(instance_id_info.release()));
+  if (registrations_iter == gcm_client()->registrations_.end())
+    return false;
+  const InstanceIDTokenInfo* instance_id_token_info =
+      InstanceIDTokenInfo::FromRegistrationInfo(
+          registrations_iter->first.get());
+  // Compare use_subtype since RegistrationInfoComparer::operator() does not.
+  return instance_id_token_info &&
+         instance_id_token_info->use_subtype == use_subtype;
 }
 
 TEST_F(GCMClientInstanceIDTest, GetToken) {
   AddInstanceID(kAppId, kInstanceID);
 
   // Get a token.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
-  GetToken(kAppId, kSender, kScope);
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+  GetToken(kAppId, false /* use_subtype */, kSender, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
 
   EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ("token1", last_registration_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
 
   // Get another token.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender2, kScope));
-  GetToken(kAppId, kSender2, kScope);
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
+  GetToken(kAppId, false /* use_subtype */, kSender2, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token2"));
 
   EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ("token2", last_registration_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
-  EXPECT_TRUE(ExistsToken(kAppId, kSender2, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
   // The 1st token still exists.
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+}
+
+TEST_F(GCMClientInstanceIDTest, GetTokenWithAndWithoutSubtype) {
+  EXPECT_EQ(GCMClientImpl::READY, gcm_client_state());
+
+  AddInstanceID(kAppId, kInstanceID);
+
+  EXPECT_FALSE(ExistsToken(kAppId, false, kSender, kScope));
+  EXPECT_FALSE(ExistsToken(kAppId, true, kSender, kScope));
+
+  DLOG(INFO) << "THIS TEST USES EXPECT_DCHECK - IGNORE STACKTRACES LOGGED DUE "
+                "TO \"Registering the same Instance ID token both with and "
+                "without subtypes is not supported\" SINCE THOSE ARE EXPECTED";
+
+  for (bool use_subtype : {false, true}) {
+    // Get a token.
+    GetToken(kAppId, use_subtype, kSender, kScope);
+    ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
+    EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
+    EXPECT_EQ(kAppId, last_app_id());
+    EXPECT_EQ("token1", last_registration_id());
+    EXPECT_EQ(GCMClient::SUCCESS, last_result());
+    EXPECT_TRUE(ExistsToken(kAppId, use_subtype, kSender, kScope));
+    EXPECT_FALSE(ExistsToken(kAppId, !use_subtype, kSender, kScope));
+
+    // Getting the same token with opposite value of use_subtype should assert.
+    EXPECT_DCHECK(
+        { GetToken(kAppId, !use_subtype, kSender, kScope); },
+        "Registering the same Instance ID token both with and without subtypes "
+        "is not supported");
+
+    // Deletion should work. Clean up for next loop iteration.
+    DeleteToken(kAppId, use_subtype, kSender, kScope);
+    ASSERT_NO_FATAL_FAILURE(CompleteDeleteToken());
+    EXPECT_FALSE(ExistsToken(kAppId, use_subtype, kSender, kScope));
+    EXPECT_FALSE(ExistsToken(kAppId, !use_subtype, kSender, kScope));
+  }
 }
 
 TEST_F(GCMClientInstanceIDTest, DeleteInvalidToken) {
   AddInstanceID(kAppId, kInstanceID);
 
   // Delete an invalid token.
-  DeleteToken(kAppId, "Foo@#$", kScope);
+  DeleteToken(kAppId, false /* use_subtype */, "Foo@#$", kScope);
   PumpLoopUntilIdle();
 
   EXPECT_EQ(UNREGISTRATION_COMPLETED, last_event());
@@ -1507,7 +1579,7 @@ TEST_F(GCMClientInstanceIDTest, DeleteInvalidToken) {
   reset_last_event();
 
   // Delete a non-existing token.
-  DeleteToken(kAppId, kSender, kScope);
+  DeleteToken(kAppId, false /* use_subtype */, kSender, kScope);
   PumpLoopUntilIdle();
 
   EXPECT_EQ(UNREGISTRATION_COMPLETED, last_event());
@@ -1519,61 +1591,61 @@ TEST_F(GCMClientInstanceIDTest, DeleteSingleToken) {
   AddInstanceID(kAppId, kInstanceID);
 
   // Get a token.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
-  GetToken(kAppId, kSender, kScope);
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+  GetToken(kAppId, false /* use_subtype */, kSender, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
 
   EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ("token1", last_registration_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
 
   reset_last_event();
 
   // Get another token.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender2, kScope));
-  GetToken(kAppId, kSender2, kScope);
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
+  GetToken(kAppId, false /* use_subtype */, kSender2, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token2"));
 
   EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ("token2", last_registration_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
-  EXPECT_TRUE(ExistsToken(kAppId, kSender2, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
   // The 1st token still exists.
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
 
   reset_last_event();
 
   // Delete the 2nd token.
-  DeleteToken(kAppId, kSender2, kScope);
+  DeleteToken(kAppId, false /* use_subtype */, kSender2, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteDeleteToken());
 
   EXPECT_EQ(UNREGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
   // The 2nd token is gone while the 1st token still exists.
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
-  EXPECT_FALSE(ExistsToken(kAppId, kSender2, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
 
   reset_last_event();
 
   // Delete the 1st token.
-  DeleteToken(kAppId, kSender, kScope);
+  DeleteToken(kAppId, false /* use_subtype */, kSender, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteDeleteToken());
 
   EXPECT_EQ(UNREGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
   // Both tokens are gone now.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
 
   reset_last_event();
 
   // Trying to delete the token again will get an error.
-  DeleteToken(kAppId, kSender, kScope);
+  DeleteToken(kAppId, false /* use_subtype */, kSender, kScope);
   PumpLoopUntilIdle();
 
   EXPECT_EQ(UNREGISTRATION_COMPLETED, last_event());
@@ -1585,50 +1657,50 @@ TEST_F(GCMClientInstanceIDTest, DeleteAllTokens) {
   AddInstanceID(kAppId, kInstanceID);
 
   // Get a token.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
-  GetToken(kAppId, kSender, kScope);
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+  GetToken(kAppId, false /* use_subtype */, kSender, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
 
   EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ("token1", last_registration_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
 
   reset_last_event();
 
   // Get another token.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender2, kScope));
-  GetToken(kAppId, kSender2, kScope);
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
+  GetToken(kAppId, false /* use_subtype */, kSender2, kScope);
   ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token2"));
 
   EXPECT_EQ(REGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ("token2", last_registration_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
-  EXPECT_TRUE(ExistsToken(kAppId, kSender2, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
   // The 1st token still exists.
-  EXPECT_TRUE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_TRUE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
 
   reset_last_event();
 
   // Delete all tokens.
-  DeleteToken(kAppId, "*", "*");
+  DeleteToken(kAppId, false /* use_subtype */, "*", "*");
   ASSERT_NO_FATAL_FAILURE(CompleteDeleteToken());
 
   EXPECT_EQ(UNREGISTRATION_COMPLETED, last_event());
   EXPECT_EQ(kAppId, last_app_id());
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
   // All tokens are gone now.
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
-  EXPECT_FALSE(ExistsToken(kAppId, kSender, kScope));
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender, kScope));
+  EXPECT_FALSE(ExistsToken(kAppId, false /* use_subtype */, kSender2, kScope));
 }
 
 TEST_F(GCMClientInstanceIDTest, DeleteAllTokensBeforeGetAnyToken) {
   AddInstanceID(kAppId, kInstanceID);
 
   // Delete all tokens without getting a token first.
-  DeleteToken(kAppId, "*", "*");
+  DeleteToken(kAppId, false /* use_subtype */, "*", "*");
   // No need to call CompleteDeleteToken since unregistration request should
   // not be triggered.
   PumpLoopUntilIdle();
@@ -1638,4 +1710,153 @@ TEST_F(GCMClientInstanceIDTest, DeleteAllTokensBeforeGetAnyToken) {
   EXPECT_EQ(GCMClient::SUCCESS, last_result());
 }
 
+TEST_F(GCMClientInstanceIDTest, DispatchDownstreamMessageWithoutSubtype) {
+  AddInstanceID(kAppId, kInstanceID);
+  GetToken(kAppId, false /* use_subtype */, kSender, kScope);
+  ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
+  GetToken(kAppId, false /* use_subtype */, kSender2, kScope);
+  ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token2"));
+
+  std::map<std::string, std::string> expected_data;
+
+  // Message for kSender with a subtype will be dropped.
+  MCSMessage message0(BuildDownstreamMessage(
+      kSender, kCategoryForSubtypes, kAppId /* subtype */, expected_data,
+      std::string() /* raw_data */));
+  EXPECT_TRUE(message0.IsValid());
+  ReceiveMessageFromMCS(message0);
+
+  EXPECT_NE(MESSAGE_RECEIVED, last_event());
+
+  reset_last_event();
+
+  // Message for kSender will be received.
+  MCSMessage message1(
+      BuildDownstreamMessage(kSender, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
+  EXPECT_TRUE(message1.IsValid());
+  ReceiveMessageFromMCS(message1);
+
+  EXPECT_EQ(MESSAGE_RECEIVED, last_event());
+  EXPECT_EQ(kAppId, last_app_id());
+  EXPECT_EQ(expected_data.size(), last_message().data.size());
+  EXPECT_EQ(expected_data, last_message().data);
+  EXPECT_EQ(kSender, last_message().sender_id);
+
+  reset_last_event();
+
+  // Message for kSender2 will be received.
+  MCSMessage message2(
+      BuildDownstreamMessage(kSender2, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
+  EXPECT_TRUE(message2.IsValid());
+  ReceiveMessageFromMCS(message2);
+
+  EXPECT_EQ(MESSAGE_RECEIVED, last_event());
+  EXPECT_EQ(kAppId, last_app_id());
+  EXPECT_EQ(expected_data.size(), last_message().data.size());
+  EXPECT_EQ(expected_data, last_message().data);
+  EXPECT_EQ(kSender2, last_message().sender_id);
+
+  reset_last_event();
+
+  // Message from kSender3 will be dropped.
+  MCSMessage message3(
+      BuildDownstreamMessage(kSender3, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
+  EXPECT_TRUE(message3.IsValid());
+  ReceiveMessageFromMCS(message3);
+
+  EXPECT_NE(MESSAGE_RECEIVED, last_event());
+  EXPECT_NE(kAppId, last_app_id());
+}
+
+TEST_F(GCMClientInstanceIDTest, DispatchDownstreamMessageWithSubtype) {
+  AddInstanceID(kAppId, kInstanceID);
+  GetToken(kAppId, true /* use_subtype */, kSender, kScope);
+  ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
+  GetToken(kAppId, true /* use_subtype */, kSender2, kScope);
+  ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token2"));
+
+  std::map<std::string, std::string> expected_data;
+
+  // Message for kSender without a subtype will be dropped.
+  MCSMessage message0(
+      BuildDownstreamMessage(kSender, kAppId, std::string() /* subtype */,
+                             expected_data, std::string() /* raw_data */));
+  EXPECT_TRUE(message0.IsValid());
+  ReceiveMessageFromMCS(message0);
+
+  EXPECT_NE(MESSAGE_RECEIVED, last_event());
+
+  reset_last_event();
+
+  // Message for kSender will be received.
+  MCSMessage message1(BuildDownstreamMessage(
+      kSender, kCategoryForSubtypes, kAppId /* subtype */, expected_data,
+      std::string() /* raw_data */));
+  EXPECT_TRUE(message1.IsValid());
+  ReceiveMessageFromMCS(message1);
+
+  EXPECT_EQ(MESSAGE_RECEIVED, last_event());
+  EXPECT_EQ(kAppId, last_app_id());
+  EXPECT_EQ(expected_data.size(), last_message().data.size());
+  EXPECT_EQ(expected_data, last_message().data);
+  EXPECT_EQ(kSender, last_message().sender_id);
+
+  reset_last_event();
+
+  // Message for kSender2 will be received.
+  MCSMessage message2(BuildDownstreamMessage(
+      kSender2, kCategoryForSubtypes, kAppId /* subtype */, expected_data,
+      std::string() /* raw_data */));
+  EXPECT_TRUE(message2.IsValid());
+  ReceiveMessageFromMCS(message2);
+
+  EXPECT_EQ(MESSAGE_RECEIVED, last_event());
+  EXPECT_EQ(kAppId, last_app_id());
+  EXPECT_EQ(expected_data.size(), last_message().data.size());
+  EXPECT_EQ(expected_data, last_message().data);
+  EXPECT_EQ(kSender2, last_message().sender_id);
+
+  reset_last_event();
+
+  // Message from kSender3 will be dropped.
+  MCSMessage message3(BuildDownstreamMessage(
+      kSender3, kCategoryForSubtypes, kAppId /* subtype */, expected_data,
+      std::string() /* raw_data */));
+  EXPECT_TRUE(message3.IsValid());
+  ReceiveMessageFromMCS(message3);
+
+  EXPECT_NE(MESSAGE_RECEIVED, last_event());
+  EXPECT_NE(kAppId, last_app_id());
+}
+
+TEST_F(GCMClientInstanceIDTest, DispatchDownstreamMessageWithFakeSubtype) {
+  AddInstanceID("victim_app_id", "iid_1");
+  GetToken("victim_app_id", true /* use_subtype */, kSender, kScope);
+  ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token1"));
+
+  AddInstanceID("evil_app_id", "iid_2");
+  GetToken("evil_app_id", false /* use_subtype */, kSender, kScope);
+  ASSERT_NO_FATAL_FAILURE(CompleteRegistration("token2"));
+
+  std::map<std::string, std::string> expected_data;
+
+  // Message for "evil_app_id" should be delivered to evil app rather than
+  // victim app, despite the malicious subtype property attempting to
+  // impersonate victim app.
+  MCSMessage message(BuildDownstreamMessage(
+      kSender, "evil_app_id" /* category */, "victim_app_id" /* subtype */,
+      expected_data, std::string() /* raw_data */));
+  EXPECT_TRUE(message.IsValid());
+  ReceiveMessageFromMCS(message);
+
+  EXPECT_EQ(MESSAGE_RECEIVED, last_event());
+  EXPECT_EQ("evil_app_id", last_app_id());
+  EXPECT_EQ(expected_data.size(), last_message().data.size());
+  EXPECT_EQ(expected_data, last_message().data);
+  EXPECT_EQ(kSender, last_message().sender_id);
+}
+
 }  // namespace gcm