cros: Add UMA metrics in migration UI to get more information from migration failures.

chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
index e47c7ad10f96d3a801b44b0f14e9630dd8d51b20..5209e73bf1ce60e839de1e5de3a47b680a544c0e 100644
--- a/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/encryption_migration_screen_handler.cc
@@ -12,10 +12,13 @@
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/metrics/user_metrics.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/sys_info.h"
 #include "base/task_scheduler/post_task.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/arc/arc_migration_constants.h"
 #include "chrome/browser/chromeos/login/ui/login_feedback.h"
@@ -46,17 +49,22 @@ constexpr char kCheckStoragePath[] = "/home";
 constexpr char kJsApiStartMigration[] = "startMigration";
 constexpr char kJsApiSkipMigration[] = "skipMigration";
 constexpr char kJsApiRequestRestart[] = "requestRestart";
+constexpr char kJsApiRequestRestartOnFailure[] = "requestRestartOnFailure";
 constexpr char kJsApiOpenFeedbackDialog[] = "openFeedbackDialog";
 
 // UMA names.
 constexpr char kUmaNameFirstScreen[] = "Cryptohome.MigrationUI.FirstScreen";
 constexpr char kUmaNameUserChoice[] = "Cryptohome.MigrationUI.UserChoice";
+constexpr char kUmaNameMigrationResult[] =
+    "Cryptohome.MigrationUI.MigrationResult";
+constexpr char kUmaNameRemoveCryptohomeResult[] =
+    "Cryptohome.MigrationUI.RemoveCryptohomeResult";
 constexpr char kUmaNameConsumedBatteryPercent[] =
     "Cryptohome.MigrationUI.ConsumedBatteryPercent";
 
-// This enum must match the numbering for Cryptohome.MigrationUI.FirstScreen in
-// histograms.xml. Do not reorder or remove items, only add new items before
-// FIRST_SCREEN_MAX.
+// This enum must match the numbering for MigrationUIFirstScreen in
+// histograms/enums.xml. Do not reorder or remove items, only add new items
+// before FIRST_SCREEN_COUNT.
 enum class FirstScreen {
   FIRST_SCREEN_READY = 0,
   FIRST_SCREEN_RESUME = 1,
@@ -64,15 +72,37 @@ enum class FirstScreen {
   FIRST_SCREEN_COUNT
 };
 
-// This enum must match the numbering for Cryptohome.MigrationUI.UserChoice in
-// histograms.xml. Do not reorder or remove items, only add new items before
-// FIRST_SCREEN_MAX.
+// This enum must match the numbering for MigrationUIUserChoice in
+// histograms/enums.xml. Do not reorder or remove items, only add new items
+// before USER_CHOICE_COUNT.
 enum class UserChoice {
   USER_CHOICE_UPDATE = 0,
   USER_CHOICE_SKIP = 1,
   USER_CHOICE_COUNT
 };
 
+// This enum must match the numbering for MigrationUIMigrationResult in
+// histograms/enums.xml. Do not reorder or remove items, only add new items
+// before COUNT.
+enum class MigrationResult {

[fukino, 2017/05/31 12:21:28]

MigrationResult and RemoveCryptohomeResult have the same set of potential
results.
However, this may differ when we get more information about the result of each
operation, so I prepared enums separately.

+  SUCCESS_IN_NEW_MIGRATION = 0,
+  SUCCESS_IN_RESUMED_MIGRATION = 1,
+  FAILURE_IN_NEW_MIGRATION = 2,
+  FAILURE_IN_RESUMED_MIGRATION = 3,
+  COUNT
+};
+
+// This enum must match the numbering for MigrationUIRemoveCryptohomeResult in
+// histograms/enums.xml. Do not reorder or remove items, only add new items
+// before COUNT.
+enum class RemoveCryptohomeResult {
+  SUCCESS_IN_NEW_MIGRATION = 0,
+  SUCCESS_IN_RESUMED_MIGRATION = 1,
+  FAILURE_IN_NEW_MIGRATION = 2,
+  FAILURE_IN_RESUMED_MIGRATION = 3,
+  COUNT
+};
+
 bool IsTestingUI() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kTestEncryptionMigrationUI);
@@ -89,6 +119,36 @@ void RecordUserChoice(UserChoice user_choice) {
                             static_cast<int>(UserChoice::USER_CHOICE_COUNT));
 }
 
+void RecordMigrationResult(bool success, bool is_resumed_migration) {
+  MigrationResult result =
+      success ? (is_resumed_migration
+                     ? MigrationResult::SUCCESS_IN_RESUMED_MIGRATION
+                     : MigrationResult::SUCCESS_IN_NEW_MIGRATION)
+              : (is_resumed_migration
+                     ? MigrationResult::FAILURE_IN_RESUMED_MIGRATION
+                     : MigrationResult::FAILURE_IN_NEW_MIGRATION);
+  UMA_HISTOGRAM_ENUMERATION(kUmaNameMigrationResult, static_cast<int>(result),
+                            static_cast<int>(MigrationResult::COUNT));

[Ilya Sherman, 2017/05/31 23:34:44]

nit: static_casts shouldn't be needed anymore when using enum classes with
UMA_HISTOGRAM_ENUMERATION macros.

[fukino, 2017/06/01 09:28:38]

Done.

+}
+
+void RecordRemoveCryptohomeResult(bool success, bool is_resumed_migration) {
+  RemoveCryptohomeResult result =
+      success ? (is_resumed_migration
+                     ? RemoveCryptohomeResult::SUCCESS_IN_RESUMED_MIGRATION
+                     : RemoveCryptohomeResult::SUCCESS_IN_NEW_MIGRATION)
+              : (is_resumed_migration
+                     ? RemoveCryptohomeResult::FAILURE_IN_RESUMED_MIGRATION
+                     : RemoveCryptohomeResult::FAILURE_IN_NEW_MIGRATION);
+  UMA_HISTOGRAM_ENUMERATION(kUmaNameRemoveCryptohomeResult,
+                            static_cast<int>(result),
+                            static_cast<int>(RemoveCryptohomeResult::COUNT));
+}
+
+void RecordShowFailureScreen() {
+  base::RecordAction(
+      base::UserMetricsAction("Cryptohome.MigrationUI.ShowFailureScreen"));
+}
+
 }  // namespace
 
 namespace chromeos {
@@ -205,6 +265,8 @@ void EncryptionMigrationScreenHandler::RegisterMessages() {
               &EncryptionMigrationScreenHandler::HandleSkipMigration);
   AddCallback(kJsApiRequestRestart,
               &EncryptionMigrationScreenHandler::HandleRequestRestart);
+  AddCallback(kJsApiRequestRestartOnFailure,
+              &EncryptionMigrationScreenHandler::HandleRequestRestartOnFailure);
   AddCallback(kJsApiOpenFeedbackDialog,
               &EncryptionMigrationScreenHandler::HandleOpenFeedbackDialog);
 }
@@ -261,6 +323,12 @@ void EncryptionMigrationScreenHandler::HandleRequestRestart() {
   DBusThreadManager::Get()->GetPowerManagerClient()->RequestRestart();
 }
 
+void EncryptionMigrationScreenHandler::HandleRequestRestartOnFailure() {
+  base::RecordAction(base::UserMetricsAction(
+      "Cryptohome.MigrationUI.RestartClickedOnFailure"));
+  DBusThreadManager::Get()->GetPowerManagerClient()->RequestRestart();
+}
+
 void EncryptionMigrationScreenHandler::HandleOpenFeedbackDialog() {
   const std::string description = base::StringPrintf(
       "Auto generated feedback for http://crbug.com/719266.\n"
@@ -398,6 +466,7 @@ void EncryptionMigrationScreenHandler::OnRemoveCryptohome(
     cryptohome::MountError return_code) {
   LOG_IF(ERROR, !success) << "Removing cryptohome failed. return code: "
                           << return_code;
+  RecordRemoveCryptohomeResult(success, should_resume_);
   UpdateUIState(UIState::MIGRATION_FAILED);
 }
 
@@ -429,6 +498,7 @@ void EncryptionMigrationScreenHandler::OnMigrationProgress(
       CallJS("setMigrationProgress", static_cast<double>(current) / total);
       break;
     case cryptohome::DIRCRYPTO_MIGRATION_SUCCESS:
+      RecordMigrationResult(true, should_resume_);
       // If the battery level decreased during migration, record the consumed
       // battery level.
       if (*current_battery_percent_ < initial_battery_percent_) {
@@ -441,6 +511,15 @@ void EncryptionMigrationScreenHandler::OnMigrationProgress(
       DBusThreadManager::Get()->GetPowerManagerClient()->RequestRestart();
       break;
     case cryptohome::DIRCRYPTO_MIGRATION_FAILED:
+      RecordMigrationResult(false, should_resume_);
+      // Record an event that the user sees the failure screen.
+      // We record it after delay to make sure that the user was actually able
+      // to see the failure screen. There is a potential race condition where
+      // the user can see only flash of failure screen on shutting down.
+      // crbug.com/727980.
+      base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+          FROM_HERE, base::BindOnce(&RecordShowFailureScreen),
+          base::TimeDelta::FromSeconds(1));
       // Stop listening to the progress updates.
       DBusThreadManager::Get()
           ->GetCryptohomeClient()