Add a method to remount all removable devices in DiskMountManager.

chromeos/disks/disk_mount_manager_unittest.cc

Index: chromeos/disks/disk_mount_manager_unittest.cc
diff --git a/chromeos/disks/disk_mount_manager_unittest.cc b/chromeos/disks/disk_mount_manager_unittest.cc
index ac68206428ee754f489c51ef8f1211c0b019c82f..56a285668fd34a25e5f65f2785d77526bafad38d 100644
--- a/chromeos/disks/disk_mount_manager_unittest.cc
+++ b/chromeos/disks/disk_mount_manager_unittest.cc
@@ -895,4 +895,41 @@ TEST_F(DiskMountManagerTest, MountPath_ReadOnlyDevice) {
   EXPECT_TRUE(disks.find(kReadOnlyDeviceSourcePath)->second->is_read_only());
 }
 
+TEST_F(DiskMountManagerTest, RemountRemovableDrives) {
+  DiskMountManager* manager = DiskMountManager::GetInstance();
+  manager->RemountAllRemovableDrives(chromeos::MOUNT_ACCESS_MODE_READ_ONLY);
+
+  // Simulate cros_disks reporting mount completed.
+  fake_cros_disks_client_->SendMountCompletedEvent(
+      chromeos::MOUNT_ERROR_NONE, kDevice1SourcePath,
+      chromeos::MOUNT_TYPE_DEVICE, kDevice1MountPath);
+
+  // Should remount all devices but read-only hardwares.
+  ASSERT_EQ(1U, observer_->GetEventCount());
+  VerifyMountEvent(observer_->GetMountEvent(0), DiskMountManager::MOUNTING,
+                   chromeos::MOUNT_ERROR_NONE, kDevice1MountPath);
+  // The device is remounted in read-only mode.
+  EXPECT_TRUE(
+      manager->FindDiskBySourcePath(kDevice1SourcePath)->is_read_only());
+  // Remounted disk should also appear as read-only to observers.
+  EXPECT_TRUE(observer_->GetMountEvent(0).disk->is_read_only());
+
+  // Remount in read-write mode again.
+  manager->RemountAllRemovableDrives(chromeos::MOUNT_ACCESS_MODE_READ_WRITE);
+
+  // Simulate cros_disks reporting mount completed.
+  fake_cros_disks_client_->SendMountCompletedEvent(
+      chromeos::MOUNT_ERROR_NONE, kDevice1SourcePath,
+      chromeos::MOUNT_TYPE_DEVICE, kDevice1MountPath);
+  // Event handlers of observers should be called.
+  ASSERT_EQ(2U, observer_->GetEventCount());
+  VerifyMountEvent(observer_->GetMountEvent(1), DiskMountManager::MOUNTING,
+                   chromeos::MOUNT_ERROR_NONE, kDevice1MountPath);
+  // The read-write device should be remounted in read-write mode.
+  EXPECT_FALSE(
+      manager->FindDiskBySourcePath(kDevice1SourcePath)->is_read_only());
+  // Remounted disk should also appear as writable to observers.
+  EXPECT_FALSE(observer_->GetMountEvent(1).disk->is_read_only());
+}
+
 }  // namespace