Make Plugin VM installer check for existing VM

The Plugin VM installer currently fails if a VM already exists. This can
happen if the user manually sets up a VM via vmc. This CL updates the
installer so that it first checks whether a VM exists, and proceeds to
the finished state immediately if so.

Bug: 1038816
Change-Id: I19381288c7fd2f2beaa82ffdb72ae5102d1f4c0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2014203
Commit-Queue: Timothy Loh <timloh@chromium.org>
Reviewed-by: Julian Watson <juwa@google.com>
Cr-Commit-Position: refs/heads/master@{#733911}

chrome/browser/chromeos/plugin_vm/plugin_vm_installer.cc

@@ -69,7 +69,13 @@ void PluginVmInstaller::Start() {
     return;
   }
 
-  StartDlcDownload();
+  // If there's an existing VM, we can complete without running the install
+  // flow.
+  PluginVmManager::GetForProfile(profile_)->UpdateVmState(
+      base::BindOnce(&PluginVmInstaller::OnUpdateVmState,
+                     weak_ptr_factory_.GetWeakPtr()),
+      base::BindOnce(&PluginVmInstaller::StartDlcDownload,
+                     weak_ptr_factory_.GetWeakPtr()));
 }
 
 void PluginVmInstaller::Cancel() {
@@ -90,6 +96,18 @@ void PluginVmInstaller::Cancel() {
   }
 }
 
+void PluginVmInstaller::OnUpdateVmState(bool default_vm_exists) {
+  if (default_vm_exists) {
+    if (observer_)
+      observer_->OnVmExists();
+    profile_->GetPrefs()->SetBoolean(plugin_vm::prefs::kPluginVmImageExists,
+                                     true);
+    state_ = State::CONFIGURED;
+    return;
+  }
+  StartDlcDownload();
+}
+
 void PluginVmInstaller::StartDlcDownload() {
   state_ = State::DOWNLOADING_DLC;
   dlc_download_start_tick_ = base::TimeTicks::Now();

chrome/browser/chromeos/plugin_vm/plugin_vm_installer.h

@@ -66,6 +66,10 @@ class PluginVmInstaller : public KeyedService,
   class Observer {
    public:
     virtual ~Observer() = default;
+
+    // If a VM already exists, we call this and abort the installation process.
+    virtual void OnVmExists() = 0;
+
     virtual void OnDlcDownloadProgressUpdated(double progress,
                                               base::TimeDelta elapsed_time) = 0;
     virtual void OnDlcDownloadCompleted() = 0;
@@ -129,6 +133,7 @@ class PluginVmInstaller : public KeyedService,
   std::string GetCurrentDownloadGuidForTesting();
 
  private:
+  void OnUpdateVmState(bool default_vm_exists);
   void StartDlcDownload();
   void StartDownload();
   void StartImport();

chrome/browser/chromeos/plugin_vm/plugin_vm_installer_unittest.cc

@@ -29,6 +29,7 @@
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "chromeos/dbus/dlcservice/fake_dlcservice_client.h"
 #include "chromeos/dbus/fake_concierge_client.h"
+#include "chromeos/dbus/fake_vm_plugin_dispatcher_client.h"
 #include "components/account_id/account_id.h"
 #include "components/download/public/background_service/test/test_download_service.h"
 #include "components/drive/service/dummy_drive_service.h"
@@ -70,6 +71,7 @@ const int kDownloadedPluginVmImageSizeInMb = 123456789u / (1024 * 1024);
 
 class MockObserver : public PluginVmInstaller::Observer {
  public:
+  MOCK_METHOD0(OnVmExists, void());
   MOCK_METHOD2(OnDlcDownloadProgressUpdated,
                void(double progress, base::TimeDelta elapsed_time));
   MOCK_METHOD0(OnDlcDownloadCompleted, void());
@@ -380,6 +382,19 @@ class PluginVmInstallerDriveTest : public PluginVmInstallerTestBase {
   DISALLOW_COPY_AND_ASSIGN(PluginVmInstallerDriveTest);
 };
 
+TEST_F(PluginVmInstallerDownloadServiceTest, VmExists) {
+  vm_tools::plugin_dispatcher::ListVmResponse list_vms_response;
+  list_vms_response.add_vm_info()->set_state(
+      vm_tools::plugin_dispatcher::VmState::VM_STATE_STOPPED);
+  static_cast<chromeos::FakeVmPluginDispatcherClient*>(
+      chromeos::DBusThreadManager::Get()->GetVmPluginDispatcherClient())
+      ->set_list_vms_response(list_vms_response);
+
+  EXPECT_CALL(*observer_, OnVmExists());
+  EXPECT_CALL(*observer_, OnDlcDownloadCompleted()).Times(0);
+  StartAndRunToCompletion();
+}
+
 TEST_F(PluginVmInstallerDownloadServiceTest, DownloadPluginVmImageParamsTest) {
   SetupConciergeForSuccessfulDiskImageImport(fake_concierge_client_);
 

chrome/browser/chromeos/plugin_vm/plugin_vm_metrics_util.h

@@ -44,7 +44,9 @@ enum class PluginVmSetupResult {
   kErrorDownloadingPluginVmDlc = 6,
   kUserCancelledDownloadingPluginVmDlc = 7,
 
-  kMaxValue = kUserCancelledDownloadingPluginVmDlc,
+  kVmAlreadyExists = 8,
+
+  kMaxValue = kVmAlreadyExists,
 };
 
 enum class PluginVmDlcUseResult {

chrome/browser/ui/views/plugin_vm/plugin_vm_installer_view.cc

@@ -222,6 +222,19 @@ gfx::Size PluginVmInstallerView::CalculatePreferredSize() const {
   return gfx::Size(kWindowWidth, kWindowHeight);
 }
 
+void PluginVmInstallerView::OnVmExists() {
+  // This case should only occur if the user manually installed a VM via vmc,
+  // which is rare enough so we just re-use the regular success strings.
+  DCHECK_EQ(state_, State::DOWNLOADING_DLC);
+  state_ = State::FINISHED;
+  OnStateUpdated();
+
+  plugin_vm::RecordPluginVmSetupResultHistogram(
+      plugin_vm::PluginVmSetupResult::kVmAlreadyExists);
+  plugin_vm::RecordPluginVmSetupTimeHistogram(base::TimeTicks::Now() -
+                                              setup_start_tick_);
+}
+
 void PluginVmInstallerView::OnDlcDownloadProgressUpdated(
     double progress,
     base::TimeDelta elapsed_time) {

chrome/browser/ui/views/plugin_vm/plugin_vm_installer_view.h

@@ -33,6 +33,7 @@ class PluginVmInstallerView : public views::BubbleDialogDelegateView,
   gfx::Size CalculatePreferredSize() const override;
 
   // plugin_vm::PluginVmImageDownload::Observer implementation.
+  void OnVmExists() override;
   void OnDlcDownloadProgressUpdated(double progress,
                                     base::TimeDelta elapsed_time) override;
   void OnDlcDownloadCompleted() override;

tools/metrics/histograms/enums.xml

@@ -50768,6 +50768,7 @@ Called by update_net_trust_anchors.py.-->
   <int value="5" label="User cancelled setup while importing Plugin VM image"/>
   <int value="6" label="Error while downloading Plugin VM DLC"/>
   <int value="7" label="User cancelled setup while downloading Plugin VM DLC"/>
+  <int value="8" label="Plugin VM was already installed"/>
 </enum>
 
 <enum name="PNaClOptionsOptLevelEnum">