[CrOS PhoneHub] Provide an instance of PhoneHubManager to SystemTray

This CL removes PhoneHubManager::Get(), and instead provides
PhoneHubManager to //ash via new function
SystemTray::SetPhoneHubManager().

This function is left as a TODO for now; a follow-up CL will use the
provided PhoneHubManager pointer to render the UI in //ash.

Bug: 1106937
Change-Id: I4a69d700d4e086d3e59ceaaf5ae1a364824a3633
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2368485Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800779}

ash/public/cpp/system_tray.h

@@ -10,6 +10,12 @@
 #include "ash/public/cpp/ash_public_export.h"
 #include "base/strings/string16.h"
 
+namespace chromeos {
+namespace phonehub {
+class PhoneHubManager;
+}  // namespace phonehub
+}  // namespace chromeos
+
 namespace ash {
 
 struct LocaleInfo;
@@ -101,6 +107,10 @@ class ASH_PUBLIC_EXPORT SystemTray {
   // click (it is used e.g. for timing histograms).
   virtual void ShowNetworkDetailedViewBubble(bool show_by_click) = 0;
 
+  // Provides Phone Hub functionality to the system tray.
+  virtual void SetPhoneHubManager(
+      chromeos::phonehub::PhoneHubManager* phone_hub_manager) = 0;
+
  protected:
   SystemTray();
   virtual ~SystemTray();

ash/system/model/system_tray_model.cc

@@ -115,4 +115,9 @@ void SystemTrayModel::ShowNetworkDetailedViewBubble(bool show_by_click) {
     system_tray->ShowNetworkDetailedViewBubble(show_by_click);
 }
 
+void SystemTrayModel::SetPhoneHubManager(
+    chromeos::phonehub::PhoneHubManager* phone_hub_manager) {
+  // TODO(tengs): Use |phone_hub_manager|.
+}
+
 }  // namespace ash

ash/system/model/system_tray_model.h

@@ -50,6 +50,8 @@ class SystemTrayModel : public SystemTray {
   void SetUpdateOverCellularAvailableIconVisible(bool visible) override;
   void ShowVolumeSliderBubble() override;
   void ShowNetworkDetailedViewBubble(bool show_by_click) override;
+  void SetPhoneHubManager(
+      chromeos::phonehub::PhoneHubManager* phone_hub_manager) override;
 
   ClockModel* clock() { return clock_.get(); }
   EnterpriseDomainModel* enterprise_domain() {

chrome/browser/chromeos/phonehub/phone_hub_manager_factory.cc

@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/phonehub/phone_hub_manager_factory.h"
 
+#include "ash/public/cpp/system_tray.h"
 #include "chrome/browser/chromeos/device_sync/device_sync_client_factory.h"
 #include "chrome/browser/chromeos/multidevice_setup/multidevice_setup_client_factory.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
@@ -74,10 +75,16 @@ KeyedService* PhoneHubManagerFactory::BuildServiceInstanceFor(
   if (IsProhibitedByPolicy(profile))
     return nullptr;
 
-  return new PhoneHubManager(
+  PhoneHubManager* phone_hub_manager = new PhoneHubManager(
       profile->GetPrefs(),
       device_sync::DeviceSyncClientFactory::GetForProfile(profile),
       multidevice_setup::MultiDeviceSetupClientFactory::GetForProfile(profile));
+
+  // Provide |phone_hub_manager| to the system tray so that it can be used by
+  // the UI.
+  ash::SystemTray::Get()->SetPhoneHubManager(phone_hub_manager);
+
+  return phone_hub_manager;
 }
 
 bool PhoneHubManagerFactory::ServiceIsCreatedWithBrowserContext() const {

chromeos/components/phonehub/phone_hub_manager.cc

@@ -13,14 +13,6 @@
 
 namespace chromeos {
 namespace phonehub {
-namespace {
-PhoneHubManager* g_instance = nullptr;
-}  // namespace
-
-// static
-PhoneHubManager* PhoneHubManager::Get() {
-  return g_instance;
-}
 
 PhoneHubManager::PhoneHubManager(
     PrefService* pref_service,
@@ -33,17 +25,11 @@ PhoneHubManager::PhoneHubManager(
           std::make_unique<NotificationAccessManagerImpl>(pref_service)),
       phone_model_(std::make_unique<MutablePhoneModel>()),
       tether_controller_(
-          std::make_unique<TetherControllerImpl>(multidevice_setup_client)) {
-  DCHECK(!g_instance);
-  g_instance = this;
-}
+          std::make_unique<TetherControllerImpl>(multidevice_setup_client)) {}
 
 PhoneHubManager::~PhoneHubManager() = default;
 
 void PhoneHubManager::Shutdown() {
-  DCHECK(g_instance);
-  g_instance = nullptr;
-
   tether_controller_.reset();
   phone_model_.reset();
   notification_access_manager_.reset();

chromeos/components/phonehub/phone_hub_manager.h

@@ -35,12 +35,6 @@ class TetherController;
 // a singleton.
 class PhoneHubManager : public KeyedService {
  public:
-  // Returns a pointer to the singleton once it has been instantiated. Returns
-  // null if the primary profile has not yet been initialized or has already
-  // shut down, if the kPhoneHub flag is disabled, or if the feature is
-  // prohibited by policy.
-  static PhoneHubManager* Get();
-
   PhoneHubManager(
       PrefService* pref_service,
       device_sync::DeviceSyncClient* device_sync_client,