crostini: Update task manager logic to identify crosvm processes

The path to disks has changed recently, so update the path we expect.

Bug: chromium:1114826
Test: Manual, CQ
Change-Id: I9f9bb5271d57021dd1c9559e9e7f858ce83dc059
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2362163
Auto-Submit: David Munro <davidmunro@google.com>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: David Munro <davidmunro@google.com>
Cr-Commit-Position: refs/heads/master@{#799437}

chrome/browser/task_manager/providers/vm/vm_process_task_provider.cc

@@ -77,7 +77,7 @@ bool CrostiniExtractVmNameAndOwnerId(const std::string& arg,
   DCHECK(owner_id_out);
 
   // All VM disk images are contained in a subdirectory of this path.
-  constexpr char kVmDiskRoot[] = "/home/root/";
+  constexpr char kVmDiskRoot[] = "/run/daemon-store";
 
   // Skip paths that don't start with the correct prefix to filter out the
   // rootfs .img file.
@@ -95,10 +95,10 @@ bool CrostiniExtractVmNameAndOwnerId(const std::string& arg,
   base::Base64Decode(vm_disk_path.RemoveExtension().BaseName().value(),
                      vm_name_out);
 
-  // The owner ID is the long hex string in there...which is 2 parents up.
+  // The owner ID is the long hex string in there...which is 1 parent up.
   // It's safe to call this even if there's not enough parents because the
   // DirName of the root is still the root.
-  *owner_id_out = vm_disk_path.DirName().DirName().BaseName().value();
+  *owner_id_out = vm_disk_path.DirName().BaseName().value();
 
   return true;
 }