borealis: switch to using dlc_id when booting

Previously we manually calculated the rootfs/kernel path using the mount
point of the DLC. This is actually done by concierge now, and we should
use it instead of re-doing the work ourselves.

Bug: b/177367054
Change-Id: Ic3137f9c0b5b3c186e84795ff64329e8b5e2a819
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2626607Reviewed-by: Daniel Ng <danielng@google.com>
Commit-Queue: Nic Hollingum <hollingum@google.com>
Cr-Commit-Position: refs/heads/master@{#843208}

chrome/browser/chromeos/borealis/borealis_context.h

@@ -38,9 +38,6 @@ class BorealisContext {
     container_name_ = std::move(container_name);
   }
 
-  const std::string& root_path() const { return root_path_; }
-  void set_root_path(std::string path) { root_path_ = std::move(path); }
-
   const base::FilePath& disk_path() const { return disk_path_; }
   void set_disk_path(base::FilePath path) { disk_path_ = std::move(path); }
 
@@ -52,7 +49,6 @@ class BorealisContext {
   Profile* const profile_;
   std::string vm_name_;
   std::string container_name_;
-  std::string root_path_;
   base::FilePath disk_path_;
   // This instance listens for the session to finish and issues an automatic
   // shutdown when it does.

chrome/browser/chromeos/borealis/borealis_task.cc

@@ -57,7 +57,6 @@ void MountDlc::OnMountDlc(
     Complete(BorealisStartupResult::kMountFailed,
              "Mounting the DLC for Borealis failed: " + install_result.error);
   } else {
-    context->set_root_path(install_result.root_path);
     Complete(BorealisStartupResult::kSuccess, "");
   }
 }
@@ -106,9 +105,7 @@ StartBorealisVm::~StartBorealisVm() = default;
 
 void StartBorealisVm::RunInternal(BorealisContext* context) {
   vm_tools::concierge::StartVmRequest request;
-  vm_tools::concierge::VirtualMachineSpec* vm = request.mutable_vm();
-  vm->set_kernel(context->root_path() + "/vm_kernel");
-  vm->set_rootfs(context->root_path() + "/vm_rootfs.img");
+  request.mutable_vm()->set_dlc_id(kBorealisDlcName);
   request.set_start_termina(false);
   request.set_owner_id(
       chromeos::ProfileHelper::GetUserIdHashFromProfile(context->profile()));

chrome/browser/chromeos/borealis/borealis_task_unittest.cc

@@ -85,8 +85,6 @@ class BorealisTasksTest : public testing::Test {
 
 TEST_F(BorealisTasksTest, MountDlcSucceedsAndCallbackRanWithResults) {
   fake_dlcservice_client_->set_install_error(dlcservice::kErrorNone);
-  fake_dlcservice_client_->set_install_root_path("test/path");
-  EXPECT_EQ(context_->root_path(), "");
 
   testing::StrictMock<CallbackForTesting> callback;
   EXPECT_CALL(callback, Callback(BorealisStartupResult::kSuccess, _));
@@ -94,8 +92,6 @@ TEST_F(BorealisTasksTest, MountDlcSucceedsAndCallbackRanWithResults) {
   MountDlc task;
   task.Run(context_.get(), callback.GetCallback());
   task_environment_.RunUntilIdle();
-
-  EXPECT_EQ(context_->root_path(), "test/path");
 }
 
 TEST_F(BorealisTasksTest, CreateDiskSucceedsAndCallbackRanWithResults) {