Reland "Support multiple receivers for Cros APIs."

This reverts commit 640009eb.

Reason for revert: The original CL looks wrongly identified as a
cause of test breakage. Even without this CL, the test is flaky.

Original change's description:
> Revert "Support multiple receivers for Cros APIs."
>
> This reverts commit 8aca3b4d.
>
> Reason for revert: I suspect the CL caused WindowOpenApiTest.PopupBlockingExtension failure
> https://ci.chromium.org/ui/p/chromium/builders/ci/linux-chromeos-dbg/22177/overview
>
> [ RUN      ] WindowOpenApiTest.PopupBlockingExtension
> 2021-01-13T05:48:40.927570Z INFO browser_tests[28993:28993]: [content_main_runner_impl.cc(1055)] Chrome is running in full browser mode.
> 2021-01-13T05:48:41.111260Z WARNING browser_tests[28993:28993]: [audio_manager_linux.cc(69)] Falling back to ALSA for audio output. PulseAudio is not available or could not be initialized.
> 2021-01-13T05:48:41.147293Z ERROR browser_tests[28993:28993]: [cras_audio_handler.cc(1627)] Failed to retrieve WBS mic deprioritized flag
> 2021-01-13T05:48:41.148942Z WARNING browser_tests[28993:29172]: [statistics_provider.cc(321)] Finished loading statistics.
> 2021-01-13T05:48:41.786294Z WARNING browser_tests[28993:28993]: [user_policy_manager_builder_chromeos.cc(123)] No policy loaded for known non-enterprise user
> 2021-01-13T05:48:42.161192Z WARNING browser_tests[28993:28993]: [merge_session_throttling_utils.cc(143)] Loading content for a profile without session restore?
> 2021-01-13T05:48:42.192143Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:42.205962Z ERROR browser_tests[28993:28993]: [proximity_auth_profile_pref_manager.cc(192)] Failed to find local state prefs for current user.
> 2021-01-13T05:48:42.726389Z WARNING browser_tests[28993:28993]: [merge_session_throttling_utils.cc(143)] Loading content for a profile without session restore?
> 2021-01-13T05:48:43.054799Z WARNING browser_tests[28993:28993]: [wallpaper_controller_client.cc(377)] Cannot get wallpaper files id in RemovePolicyWallpaper. This should never happen under normal circumstances.
> 2021-01-13T05:48:43.218141Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:43.726830Z WARNING browser_tests[29202:29284]: [http_cache_transaction.cc(1192)] Unable to open or create cache entry
> 2021-01-13T05:48:44.322210Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:44.376219Z ERROR browser_tests[28993:28993]: [plugin_vm_manager_impl.cc(141)] New session has dispatcher unexpected already running. Perhaps Chrome crashed?
> 2021-01-13T05:48:44.859368Z INFO browser_tests[28993:28993]: [key_permissions_manager_impl.cc(495)] One-time key permissions migration started for token: 0.
> 2021-01-13T05:48:44.863796Z INFO browser_tests[28993:28993]: [android_sms_pairing_state_tracker_impl.cc(72)] No Pairing cookie found
> 2021-01-13T05:48:45.010359Z ERROR browser_tests[28993:29140]: [object_proxy.cc(621)] Failed to call method: org.chromium.U2F.IsUvpaa: object_path= /org/chromium/U2F: org.freedesktop.DBus.Error.ServiceUnknown: The name org.chromium.U2F was not provided by any .service files
> 2021-01-13T05:48:45.018258Z ERROR browser_tests[28993:29172]: [als_reader.cc(47)] Missing num of als
> 2021-01-13T05:48:45.681453Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:45.682492Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:45.685002Z INFO browser_tests[28993:28993]: [key_permissions_manager_impl.cc(520)] One-time key permissions migration succeeded for token: 0.
> 2021-01-13T05:48:45.768048Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:45.769933Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:46.230042Z WARNING browser_tests[28993:28993]: [browser_util.cc(167)] Lacros-chrome is not supported
> 2021-01-13T05:48:50.078030Z ERROR browser_tests[28993:29172]: [object_proxy.cc(621)] Failed to call method: org.chromium.debugd.GetPerfOutputFd: object_path= /org/chromium/debugd: org.freedesktop.DBus.Error.ServiceUnknown: The name org.chromium.debugd was not provided by any .service files
> 2021-01-13T05:49:10.763123Z WARNING browser_tests[28993:29410]: [embedded_test_server.cc(668)] Request not handled. Returning 404: /favicon.ico
> 2021-01-13T05:49:10.833186Z WARNING browser_tests[28993:29410]: [embedded_test_server.cc(668)] Request not handled. Returning 404: /favicon.ico
> ../../chrome/browser/extensions/window_open_apitest.cc:91: Failure
> Expected equality of these values:
>   num_browsers
>     Which is: 4
>   chrome::GetBrowserCount(browser->profile())
>     Which is: 2
> Google Test trace:
> ../../chrome/browser/extensions/window_open_apitest.cc:76: WaitForTabsPopupsApps tabs:5, popups:2, app_popups:1
> Stack trace:
> #0 0x56363e71a458 extensions::WaitForTabsPopupsApps()
> #1 0x56363e71c5aa extensions::WindowOpenApiTest_PopupBlockingExtension_Test::RunTestOnMainThread()
> #2 0x563646f1d248 content::BrowserTestBase::ProxyRunTestOnMainThreadLoop()
> #3 0x563646f207ca base::internal::FunctorTraits<>::Invoke<>()
> #4 0x563646f20741 base::internal::InvokeHelper<>::MakeItSo<>()
> #5 0x563646f206e7 _ZN4base8internal7InvokerINS0_9BindStateIMN7content15BrowserTestBaseEFvvEJNS0_17UnretainedWrapperIS4_EEEEEFvvEE7RunImplIS6_NSt4__Cr5tupleIJS8_EEEJLm0EEEEvOT_OT0_NSD_16integer_sequenceImJXspT1_EEEE
> #6 0x563646f2068c base::internal::Invoker<>::RunOnce()
> #7 0x56363c76ba61 _ZNO4base12OnceCallbackIFvvEE3RunEv
> #8 0x563645c03021 ChromeBrowserMainParts::PreMainMessageLoopRunImpl()
> #9 0x563645c01fc2 ChromeBrowserMainParts::PreMainMessageLoopRun()
> #10 0x563640599fc6 chromeos::ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun()
> #11 0x7fb5dc82e9e5 content::BrowserMainLoop::PreMainMessageLoopRun()
> #12 0x7fb5dc8383ca base::internal::FunctorTraits<>::Invoke<>()
> #13 0x7fb5dc8382e1 base::internal::InvokeHelper<>::MakeItSo<>()
> #14 0x7fb5dc838267 _ZN4base8internal7InvokerINS0_9BindStateIMN7content15BrowserMainLoopEFivEJNS0_17UnretainedWrapperIS4_EEEEEFivEE7RunImplIS6_NSt4__Cr5tupleIJS8_EEEJLm0EEEEiOT_OT0_NSD_16integer_sequenceImJXspT1_EEEE
> #15 0x7fb5dc83820c base::internal::Invoker<>::RunOnce()
> #16 0x7fb5dcc03581 _ZNO4base12OnceCallbackIFivEE3RunEv
> #17 0x7fb5dda03df6 content::StartupTaskRunner::RunAllTasksNow()
> #18 0x7fb5dc82d3ad content::BrowserMainLoop::CreateStartupTasks()
> #19 0x7fb5dc83bfd3 content::BrowserMainRunnerImpl::Initialize()
> #20 0x7fb5dc82a804 content::BrowserMain()
> #21 0x7fb5de9aae56 content::RunBrowserProcessMain()
> #22 0x7fb5de9ac3c9 content::ContentMainRunnerImpl::RunBrowser()
> #23 0x7fb5de9abd27 content::ContentMainRunnerImpl::Run()
> #24 0x7fb5de9a9106 content::RunContentProcess()
> #25 0x7fb5de9a9a3d content::ContentMain()
> #26 0x563646f1cb13 content::BrowserTestBase::SetUp()
> #27 0x563645acb283 InProcessBrowserTest::SetUp()
> #28 0x563645ab3802 extensions::ExtensionBrowserTest::SetUp()
> #29 0x56364163b48b testing::internal::HandleSehExceptionsInMethodIfSupported<>()
> #30 0x56364162ee67 testing::internal::HandleExceptionsInMethodIfSupported<>()
>
>
>
> Original change's description:
> > Support multiple receivers for Cros APIs.
> >
> > With this CL, most of Cros API starts to support multiple receivers.
> > AshChromeService and LacrosChromeService are exceptions.
> >
> > Bug: 1148448
> > Test: Build and run Lacros on a DUT.
> > Change-Id: I1d1a0be111108ae15657d81ea747750a760bd2f8
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2624323
> > Reviewed-by: James Cook <jamescook@chromium.org>
> > Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#842869}
>
> TBR=jamescook@chromium.org,hidehiko@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com
>
> Change-Id: Id097eab1934d9a2afca29f249a007de57ef18d90
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 1148448
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2626229
> Reviewed-by: Maxim Kolosovskiy  <kolos@chromium.org>
> Commit-Queue: Maxim Kolosovskiy  <kolos@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#842943}

TBR=jamescook@chromium.org,hidehiko@chromium.org,kolos@chromium.org,chromium-scoped@luci-project-accounts.iam.gserviceaccount.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1148448
Change-Id: Ic2ec65fa476b9b67a705497aad1cf3f1bffa0da2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2633482Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Maxim Kolosovskiy  <kolos@chromium.org>
Commit-Queue: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844778}

chrome/browser/chromeos/crosapi/ash_chrome_service_impl.cc

@@ -46,12 +46,17 @@ AshChromeServiceImpl::AshChromeServiceImpl(
     mojo::PendingReceiver<mojom::AshChromeService> pending_receiver)
     : receiver_(this, std::move(pending_receiver)),
       device_attributes_ash_(std::make_unique<DeviceAttributesAsh>()),
+      file_manager_ash_(std::make_unique<FileManagerAsh>()),
+      keystore_service_ash_(std::make_unique<KeystoreServiceAsh>()),
+      message_center_ash_(std::make_unique<MessageCenterAsh>()),
       metrics_reporting_ash_(std::make_unique<MetricsReportingAsh>(
           g_browser_process->local_state())),
       prefs_ash_(std::make_unique<PrefsAsh>(
           g_browser_process->local_state(),
           ProfileManager::GetPrimaryUserProfile()->GetPrefs())),
       screen_manager_ash_(std::make_unique<ScreenManagerAsh>()),
+      select_file_ash_(std::make_unique<SelectFileAsh>()),
+      feedback_ash_(std::make_unique<FeedbackAsh>()),
       cert_database_ash_(std::make_unique<CertDatabaseAsh>()),
       test_controller_ash_(std::make_unique<TestControllerAsh>()),
       clipboard_ash_(std::make_unique<ClipboardAsh>()) {
@@ -94,25 +99,17 @@ void AshChromeServiceImpl::BindAccountManager(
 
 void AshChromeServiceImpl::BindFileManager(
     mojo::PendingReceiver<crosapi::mojom::FileManager> receiver) {
-  // TODO(https://crbug.com/1148448): Convert this to allow multiple,
-  // simultaneous crosapi clients. See BindScreenManager for an example.
-  file_manager_ash_ =
-      std::make_unique<crosapi::FileManagerAsh>(std::move(receiver));
+  file_manager_ash_->BindReceiver(std::move(receiver));
 }
 
 void AshChromeServiceImpl::BindKeystoreService(
     mojo::PendingReceiver<crosapi::mojom::KeystoreService> receiver) {
-  // TODO(https://crbug.com/1148448): Convert this to allow multiple,
-  // simultaneous crosapi clients. See BindScreenManager for an example.
-  keystore_service_ash_ =
-      std::make_unique<crosapi::KeystoreServiceAsh>(std::move(receiver));
+  keystore_service_ash_->BindReceiver(std::move(receiver));
 }
 
 void AshChromeServiceImpl::BindMessageCenter(
     mojo::PendingReceiver<mojom::MessageCenter> receiver) {
-  // TODO(https://crbug.com/1148448): Convert this to allow multiple,
-  // simultaneous crosapi clients. See BindScreenManager for an example.
-  message_center_ash_ = std::make_unique<MessageCenterAsh>(std::move(receiver));
+  message_center_ash_->BindReceiver(std::move(receiver));
 }
 
 void AshChromeServiceImpl::BindMetricsReporting(
@@ -122,9 +119,7 @@ void AshChromeServiceImpl::BindMetricsReporting(
 
 void AshChromeServiceImpl::BindSelectFile(
     mojo::PendingReceiver<mojom::SelectFile> receiver) {
-  // TODO(https://crbug.com/1148448): Convert this to allow multiple,
-  // simultaneous crosapi clients. See BindScreenManager for an example.
-  select_file_ash_ = std::make_unique<SelectFileAsh>(std::move(receiver));
+  select_file_ash_->BindReceiver(std::move(receiver));
 }
 
 void AshChromeServiceImpl::BindScreenManager(
@@ -139,9 +134,7 @@ void AshChromeServiceImpl::BindHidManager(
 
 void AshChromeServiceImpl::BindFeedback(
     mojo::PendingReceiver<mojom::Feedback> receiver) {
-  // TODO(https://crbug.com/1148448): Convert this to allow multiple,
-  // simultaneous crosapi clients. See BindScreenManager for an example.
-  feedback_ash_ = std::make_unique<FeedbackAsh>(std::move(receiver));
+  feedback_ash_->BindReceiver(std::move(receiver));
 }
 
 void AshChromeServiceImpl::BindMediaSessionController(

chrome/browser/chromeos/crosapi/feedback_ash.cc

@@ -23,11 +23,15 @@ chrome::FeedbackSource FromMojo(mojom::LacrosFeedbackSource source) {
 
 }  // namespace
 
-FeedbackAsh::FeedbackAsh(mojo::PendingReceiver<mojom::Feedback> receiver)
-    : receiver_(this, std::move(receiver)) {}
+FeedbackAsh::FeedbackAsh() = default;
 
 FeedbackAsh::~FeedbackAsh() = default;
 
+void FeedbackAsh::BindReceiver(
+    mojo::PendingReceiver<mojom::Feedback> receiver) {
+  receivers_.Add(this, std::move(receiver));
+}
+
 void FeedbackAsh::ShowFeedbackPage(mojom::FeedbackInfoPtr feedback_info) {
   const user_manager::User* user =
       user_manager::UserManager::Get()->GetPrimaryUser();

chrome/browser/chromeos/crosapi/feedback_ash.h

@@ -7,7 +7,7 @@
 
 #include "chromeos/crosapi/mojom/feedback.mojom.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
-#include "mojo/public/cpp/bindings/receiver.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
 
 namespace crosapi {
 
@@ -15,16 +15,18 @@ namespace crosapi {
 // UI thread. Shows feedback page in response to mojo IPCs from lacros-chrome.
 class FeedbackAsh : public mojom::Feedback {
  public:
-  explicit FeedbackAsh(mojo::PendingReceiver<mojom::Feedback> receiver);
+  FeedbackAsh();
   FeedbackAsh(const FeedbackAsh&) = delete;
   FeedbackAsh& operator=(const FeedbackAsh&) = delete;
   ~FeedbackAsh() override;
 
+  void BindReceiver(mojo::PendingReceiver<mojom::Feedback> receiver);
+
   // crosapi::mojom::Feedback:
   void ShowFeedbackPage(mojom::FeedbackInfoPtr feedback_info) override;
 
  private:
-  mojo::Receiver<mojom::Feedback> receiver_;
+  mojo::ReceiverSet<mojom::Feedback> receivers_;
 };
 
 }  // namespace crosapi

chrome/browser/chromeos/crosapi/file_manager_ash.cc

@@ -67,12 +67,15 @@ void OpenItem(const base::FilePath& path,
 
 }  // namespace
 
-FileManagerAsh::FileManagerAsh(
-    mojo::PendingReceiver<mojom::FileManager> receiver)
-    : receiver_(this, std::move(receiver)) {}
+FileManagerAsh::FileManagerAsh() = default;
 
 FileManagerAsh::~FileManagerAsh() = default;
 
+void FileManagerAsh::BindReceiver(
+    mojo::PendingReceiver<mojom::FileManager> receiver) {
+  receivers_.Add(this, std::move(receiver));
+}
+
 void FileManagerAsh::DeprecatedShowItemInFolder(const base::FilePath& path) {
   Profile* primary_profile = ProfileManager::GetPrimaryUserProfile();
   base::FilePath final_path = ExpandPath(primary_profile, path);

chrome/browser/chromeos/crosapi/file_manager_ash.h

@@ -7,7 +7,7 @@
 
 #include "chromeos/crosapi/mojom/file_manager.mojom.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
-#include "mojo/public/cpp/bindings/receiver.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
 
 namespace crosapi {
 
@@ -16,11 +16,13 @@ namespace crosapi {
 // manager, for example to open a folder or highlight a file.
 class FileManagerAsh : public mojom::FileManager {
  public:
-  explicit FileManagerAsh(mojo::PendingReceiver<mojom::FileManager> receiver);
+  FileManagerAsh();
   FileManagerAsh(const FileManagerAsh&) = delete;
   FileManagerAsh& operator=(const FileManagerAsh&) = delete;
   ~FileManagerAsh() override;
 
+  void BindReceiver(mojo::PendingReceiver<mojom::FileManager> receiver);
+
   // crosapi::mojom::FileManager:
   void DeprecatedShowItemInFolder(const base::FilePath& path) override;
   void ShowItemInFolder(const base::FilePath& path,
@@ -30,7 +32,7 @@ class FileManagerAsh : public mojom::FileManager {
   void OpenFile(const base::FilePath& path, OpenFileCallback callback) override;
 
  private:
-  mojo::Receiver<mojom::FileManager> receiver_;
+  mojo::ReceiverSet<mojom::FileManager> receivers_;
 };
 
 }  // namespace crosapi

chrome/browser/chromeos/crosapi/keystore_service_ash.cc

@@ -78,9 +78,7 @@ base::Optional<std::string> StringFromSigningAlgorithmName(
 
 }  // namespace
 
-KeystoreServiceAsh::KeystoreServiceAsh(
-    mojo::PendingReceiver<mojom::KeystoreService> receiver)
-    : receiver_(this, std::move(receiver)) {
+KeystoreServiceAsh::KeystoreServiceAsh() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 }
 
@@ -88,6 +86,11 @@ KeystoreServiceAsh::~KeystoreServiceAsh() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 }
 
+void KeystoreServiceAsh::BindReceiver(
+    mojo::PendingReceiver<mojom::KeystoreService> receiver) {
+  receivers_.Add(this, std::move(receiver));
+}
+
 void KeystoreServiceAsh::ChallengeAttestationOnlyKeystore(
     const std::string& challenge,
     mojom::KeystoreType type,

chrome/browser/chromeos/crosapi/keystore_service_ash.h

@@ -12,7 +12,7 @@
 #include "chrome/browser/chromeos/platform_keys/platform_keys.h"
 #include "chromeos/crosapi/mojom/keystore_service.mojom.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
-#include "mojo/public/cpp/bindings/receiver.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
 
 namespace chromeos {
 namespace attestation {
@@ -28,12 +28,13 @@ namespace crosapi {
 // system keystores. This class is affine to the UI thread.
 class KeystoreServiceAsh : public mojom::KeystoreService {
  public:
-  explicit KeystoreServiceAsh(
-      mojo::PendingReceiver<mojom::KeystoreService> receiver);
+  KeystoreServiceAsh();
   KeystoreServiceAsh(const KeystoreServiceAsh&) = delete;
   KeystoreServiceAsh& operator=(const KeystoreServiceAsh&) = delete;
   ~KeystoreServiceAsh() override;
 
+  void BindReceiver(mojo::PendingReceiver<mojom::KeystoreService> receiver);
+
   // mojom::KeystoreService:
   using KeystoreType = mojom::KeystoreType;
   using SigningScheme = mojom::KeystoreSigningScheme;
@@ -94,7 +95,7 @@ class KeystoreServiceAsh : public mojom::KeystoreService {
   // Container to keep outstanding challenges alive.
   std::vector<std::unique_ptr<chromeos::attestation::TpmChallengeKey>>
       outstanding_challenges_;
-  mojo::Receiver<mojom::KeystoreService> receiver_;
+  mojo::ReceiverSet<mojom::KeystoreService> receivers_;
 
   base::WeakPtrFactory<KeystoreServiceAsh> weak_factory_{this};
 };

chrome/browser/chromeos/crosapi/message_center_ash.cc

@@ -156,12 +156,15 @@ class ForwardingDelegate : public message_center::NotificationDelegate {
 
 }  // namespace
 
-MessageCenterAsh::MessageCenterAsh(
-    mojo::PendingReceiver<mojom::MessageCenter> receiver)
-    : receiver_(this, std::move(receiver)) {}
+MessageCenterAsh::MessageCenterAsh() = default;
 
 MessageCenterAsh::~MessageCenterAsh() = default;
 
+void MessageCenterAsh::BindReceiver(
+    mojo::PendingReceiver<mojom::MessageCenter> receiver) {
+  receivers_.Add(this, std::move(receiver));
+}
+
 void MessageCenterAsh::DisplayNotification(
     mojom::NotificationPtr notification,
     mojo::PendingRemote<mojom::NotificationDelegate> delegate) {

chrome/browser/chromeos/crosapi/message_center_ash.h

@@ -7,7 +7,7 @@
 
 #include "chromeos/crosapi/mojom/message_center.mojom.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
-#include "mojo/public/cpp/bindings/receiver.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
 
 namespace crosapi {
 
@@ -16,12 +16,13 @@ namespace crosapi {
 // Sends reply IPCs when the user interacts with the notifications.
 class MessageCenterAsh : public mojom::MessageCenter {
  public:
-  explicit MessageCenterAsh(
-      mojo::PendingReceiver<mojom::MessageCenter> receiver);
+  MessageCenterAsh();
   MessageCenterAsh(const MessageCenterAsh&) = delete;
   MessageCenterAsh& operator=(const MessageCenterAsh&) = delete;
   ~MessageCenterAsh() override;
 
+  void BindReceiver(mojo::PendingReceiver<mojom::MessageCenter> receiver);
+
   // crosapi::mojom::MessageCenter:
   void DisplayNotification(
       mojom::NotificationPtr notification,
@@ -31,7 +32,7 @@ class MessageCenterAsh : public mojom::MessageCenter {
       GetDisplayedNotificationsCallback callback) override;
 
  private:
-  mojo::Receiver<mojom::MessageCenter> receiver_;
+  mojo::ReceiverSet<mojom::MessageCenter> receivers_;
 };
 
 }  // namespace crosapi

chrome/browser/chromeos/crosapi/message_center_ash_unittest.cc

@@ -84,7 +84,8 @@ class MessageCenterAshTest : public testing::Test {
   // testing::Test:
   void SetUp() override {
     message_center::MessageCenter::Initialize();
-    message_center_ash_ = std::make_unique<MessageCenterAsh>(
+    message_center_ash_ = std::make_unique<MessageCenterAsh>();
+    message_center_ash_->BindReceiver(
         message_center_remote_.BindNewPipeAndPassReceiver());
   }
 

chrome/browser/chromeos/crosapi/select_file_ash.cc

@@ -167,12 +167,15 @@ class SelectFileDialogHolder : public ui::SelectFileDialog::Listener {
 
 }  // namespace
 
-// TODO(https://crbug.com/1090587): Connection error handling.
-SelectFileAsh::SelectFileAsh(mojo::PendingReceiver<mojom::SelectFile> receiver)
-    : receiver_(this, std::move(receiver)) {}
+SelectFileAsh::SelectFileAsh() = default;
 
 SelectFileAsh::~SelectFileAsh() = default;
 
+void SelectFileAsh::BindReceiver(
+    mojo::PendingReceiver<mojom::SelectFile> receiver) {
+  receivers_.Add(this, std::move(receiver));
+}
+
 void SelectFileAsh::Select(mojom::SelectFileOptionsPtr options,
                            SelectCallback callback) {
   aura::Window* owner_window = nullptr;

chrome/browser/chromeos/crosapi/select_file_ash.h

@@ -7,7 +7,7 @@
 
 #include "chromeos/crosapi/mojom/select_file.mojom.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
-#include "mojo/public/cpp/bindings/receiver.h"
+#include "mojo/public/cpp/bindings/receiver_set.h"
 
 namespace crosapi {
 
@@ -16,17 +16,19 @@ namespace crosapi {
 // file manager to provide the dialogs. Lives on the UI thread.
 class SelectFileAsh : public mojom::SelectFile {
  public:
-  explicit SelectFileAsh(mojo::PendingReceiver<mojom::SelectFile> receiver);
+  SelectFileAsh();
   SelectFileAsh(const SelectFileAsh&) = delete;
   SelectFileAsh& operator=(const SelectFileAsh&) = delete;
   ~SelectFileAsh() override;
 
+  void BindReceiver(mojo::PendingReceiver<mojom::SelectFile> receiver);
+
   // crosapi::mojom::SelectFile:
   void Select(mojom::SelectFileOptionsPtr options,
               SelectCallback callback) override;
 
  private:
-  mojo::Receiver<mojom::SelectFile> receiver_;
+  mojo::ReceiverSet<mojom::SelectFile> receivers_;
 };
 
 }  // namespace crosapi