Cache tokens inside DriveFsHost for remounts

If drivefs needs to restart there is no need to redo all the job for
oauth token minting as the previous one should still be good.

BUG=chromium:897558

Change-Id: I4e1737a94a70476c6312ff11c04b8f3f233e4512
Reviewed-on: https://chromium-review.googlesource.com/c/1293058
Commit-Queue: Sergei Datsenko <dats@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601877}

chrome/browser/chromeos/drive/drive_integration_service.cc

@@ -464,6 +464,8 @@ class DriveIntegrationService::DriveFsHolder
         drivefs_host_(profile_->GetPath(),
                       this,
                       this,
+                      base::DefaultClock::GetInstance(),
+                      chromeos::disks::DiskMountManager::GetInstance(),
                       std::make_unique<base::OneShotTimer>()) {}
 
   drivefs::DriveFsHost* drivefs_host() { return &drivefs_host_; }

chromeos/components/drivefs/drivefs_host.h

@@ -13,6 +13,7 @@
 #include "base/files/file_path.h"
 #include "base/files/scoped_file.h"
 #include "base/macros.h"
+#include "base/time/clock.h"
 #include "base/timer/timer.h"
 #include "chromeos/components/drivefs/mojom/drivefs.mojom.h"
 #include "chromeos/disks/disk_mount_manager.h"
@@ -32,6 +33,12 @@ namespace service_manager {
 class Connector;
 }  // namespace service_manager
 
+namespace chromeos {
+namespace disks {
+class DiskMountManager;
+}
+}  // namespace chromeos
+
 namespace drivefs {
 
 class DriveFsHostObserver;
@@ -94,6 +101,8 @@ class COMPONENT_EXPORT(DRIVEFS) DriveFsHost {
   DriveFsHost(const base::FilePath& profile_path,
               Delegate* delegate,
               MountObserver* mount_observer,
+              const base::Clock* clock,
+              chromeos::disks::DiskMountManager* disk_mount_manager,
               std::unique_ptr<base::OneShotTimer> timer);
   ~DriveFsHost();
 
@@ -118,6 +127,7 @@ class COMPONENT_EXPORT(DRIVEFS) DriveFsHost {
   mojom::DriveFs* GetDriveFsInterface() const;
 
  private:
+  class AccountTokenDelegate;
   class MountState;
 
   SEQUENCE_CHECKER(sequence_checker_);
@@ -127,9 +137,12 @@ class COMPONENT_EXPORT(DRIVEFS) DriveFsHost {
 
   Delegate* const delegate_;
   MountObserver* const mount_observer_;
-
+  const base::Clock* const clock_;
+  chromeos::disks::DiskMountManager* const disk_mount_manager_;
   std::unique_ptr<base::OneShotTimer> timer_;
 
+  std::unique_ptr<AccountTokenDelegate> account_token_delegate_;
+
   // State specific to the current mount, or null if not mounted.
   std::unique_ptr<MountState> mount_state_;
 

chromeos/disks/mock_disk_mount_manager.cc

@@ -56,22 +56,16 @@ std::unique_ptr<Disk::Builder> MakeDiskBuilder() {
 
 }  // namespace
 
-void MockDiskMountManager::AddObserverInternal(
-    DiskMountManager::Observer* observer) {
+void MockDiskMountManager::AddObserver(DiskMountManager::Observer* observer) {
   observers_.AddObserver(observer);
 }
 
-void MockDiskMountManager::RemoveObserverInternal(
+void MockDiskMountManager::RemoveObserver(
     DiskMountManager::Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
 MockDiskMountManager::MockDiskMountManager() {
-  ON_CALL(*this, AddObserver(_))
-      .WillByDefault(Invoke(this, &MockDiskMountManager::AddObserverInternal));
-  ON_CALL(*this, RemoveObserver(_))
-      .WillByDefault(Invoke(this,
-                            &MockDiskMountManager::RemoveObserverInternal));
   ON_CALL(*this, disks())
       .WillByDefault(Invoke(this, &MockDiskMountManager::disksInternal));
   ON_CALL(*this, mount_points())
@@ -137,10 +131,6 @@ void MockDiskMountManager::NotifyMountEvent(MountEvent event,
 }
 
 void MockDiskMountManager::SetupDefaultReplies() {
-  EXPECT_CALL(*this, AddObserver(_))
-      .Times(AnyNumber());
-  EXPECT_CALL(*this, RemoveObserver(_))
-      .Times(AnyNumber());
   EXPECT_CALL(*this, disks())
       .WillRepeatedly(ReturnRef(disks_));
   EXPECT_CALL(*this, mount_points())

chromeos/disks/mock_disk_mount_manager.h

@@ -28,8 +28,8 @@ class MockDiskMountManager : public DiskMountManager {
 
   // DiskMountManager override.
   MOCK_METHOD0(Init, void(void));
-  MOCK_METHOD1(AddObserver, void(DiskMountManager::Observer*));
-  MOCK_METHOD1(RemoveObserver, void(DiskMountManager::Observer*));
+  void AddObserver(DiskMountManager::Observer*) override;
+  void RemoveObserver(DiskMountManager::Observer*) override;
   MOCK_CONST_METHOD0(disks, const DiskMountManager::DiskMap&(void));
   MOCK_CONST_METHOD1(FindDiskBySourcePath, const Disk*(const std::string&));
   MOCK_CONST_METHOD0(mount_points,