[Password Manager] More metrics for LinuxPasswordsMigrationToEncryptionStatus

We see significant numbers of failures. There are many steps where the
migration can fail, so we will distinguish them to identify the fragile step.

Bug: 571003
Change-Id: I23703898d86fcc3ad714228ac8dbeb5ec7e4589b
Reviewed-on: https://chromium-review.googlesource.com/c/1280766Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Christos Froussios <cfroussios@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610875}

chrome/browser/password_manager/password_store_x.cc

@@ -88,6 +88,16 @@ password_manager::metrics_util::LinuxBackendMigrationStatus StepForMetrics(
       return LinuxBackendMigrationStatus::kCopiedAll;
     case PasswordStoreX::LOGIN_DB_REPLACED:
       return LinuxBackendMigrationStatus::kLoginDBReplaced;
+    case PasswordStoreX::STARTED:
+      return LinuxBackendMigrationStatus::kStarted;
+    case PasswordStoreX::POSTPONED:
+      return LinuxBackendMigrationStatus::kPostponed;
+    case PasswordStoreX::FAILED_CREATE_ENCRYPTED:
+      return LinuxBackendMigrationStatus::kFailedCreatedEncrypted;
+    case PasswordStoreX::FAILED_ACCESS_NATIVE:
+      return LinuxBackendMigrationStatus::kFailedAccessNative;
+    case PasswordStoreX::FAILED_REPLACE:
+      return LinuxBackendMigrationStatus::kFailedReplace;
   }
   NOTREACHED();
   return LinuxBackendMigrationStatus::kNotAttempted;
@@ -359,11 +369,15 @@ void PasswordStoreX::CheckMigration() {
       base::Time::Now() - migration_to_native_started);
 
   if (base::FeatureList::IsEnabled(
-          password_manager::features::kMigrateLinuxToLoginDB) &&
-      backend_) {
+          password_manager::features::kMigrateLinuxToLoginDB)) {
     // Copy passwords from the backend into the login database, using
     // encryption.
+    if (backend_) {
+      UpdateMigrationToLoginDBStep(STARTED);
       MigrateToEncryptedLoginDB();
+    } else {
+      UpdateMigrationToLoginDBStep(POSTPONED);
+    }
   }
 }
 
@@ -430,7 +444,7 @@ void PasswordStoreX::MigrateToEncryptedLoginDB() {
   if (!encrypted_login_db->Init()) {
     VLOG(1) << "Failed to init the encrypted database file. Migration "
                "aborted.";
-    UpdateMigrationToLoginDBStep(FAILED);
+    UpdateMigrationToLoginDBStep(FAILED_CREATE_ENCRYPTED);
     return;  // Serve from the native backend.
   }
 
@@ -438,7 +452,7 @@ void PasswordStoreX::MigrateToEncryptedLoginDB() {
   VLOG(1) << "Migrating all passwords to the encrypted database. Last status: "
           << migration_to_login_db_step_;
   UpdateMigrationToLoginDBStep(CopyBackendToLoginDB(encrypted_login_db.get()));
-  if (migration_to_login_db_step_ == FAILED) {
+  if (migration_to_login_db_step_ != COPIED_ALL) {
     VLOG(1) << "Migration to encryption failed.";
     base::DeleteFile(encrypted_login_db_file_, false);
     return;
@@ -454,7 +468,7 @@ void PasswordStoreX::MigrateToEncryptedLoginDB() {
   // Move the new database onto the old.
   if (!base::Move(encrypted_login_db_file_, login_db_file_)) {
     LOG(ERROR) << "Could not replace login database.";
-    UpdateMigrationToLoginDBStep(FAILED);
+    UpdateMigrationToLoginDBStep(FAILED_REPLACE);
     base::DeleteFile(encrypted_login_db_file_, false);
     return;  // Serve from the native backend.
   }
@@ -488,17 +502,17 @@ PasswordStoreX::MigrationToLoginDBStep PasswordStoreX::CopyBackendToLoginDB(
 
   if (!login_db->DeleteAndRecreateDatabaseFile()) {
     LOG(ERROR) << "Failed to create the encrypted login database file";
-    return FAILED;
+    return FAILED_CREATE_ENCRYPTED;
   }
 
   std::vector<std::unique_ptr<PasswordForm>> forms;
   if (!backend_->GetAllLogins(&forms))
-    return FAILED;
+    return FAILED_ACCESS_NATIVE;
 
   for (auto& form : forms) {
     PasswordStoreChangeList changes = login_db->AddLogin(*form);
     if (changes.empty() || changes.back().type() != PasswordStoreChange::ADD) {
-      return FAILED;
+      return FAILED_CREATE_ENCRYPTED;
     }
   }
 

chrome/browser/password_manager/password_store_x.h

@@ -41,6 +41,16 @@ class PasswordStoreX : public password_manager::PasswordStoreDefault {
     COPIED_ALL,
     // The standard login database is encrypted.
     LOGIN_DB_REPLACED,
+    // The migration is about to be attempted.
+    STARTED,
+    // No access to the native backend.
+    POSTPONED,
+    // Could not create or write into the temporary file.
+    FAILED_CREATE_ENCRYPTED,
+    // Could not read from the native backend.
+    FAILED_ACCESS_NATIVE,
+    // Could not replace old database.
+    FAILED_REPLACE,
   };
 
   // NativeBackends more or less implement the PaswordStore interface, but

chrome/browser/password_manager/password_store_x_unittest.cc

@@ -740,7 +740,12 @@ TEST_P(PasswordStoreXTest, MigrationToEncryption) {
     EXPECT_TRUE(stored_forms.empty());
     EXPECT_EQ(PasswordStoreX::LOGIN_DB_REPLACED,
               migration_step_pref_.GetValue());
-  } else {
+  } else if (GetParam() == FAILING_BACKEND) {
+    // No values should be written if we can't read the backend.
+    auto stored_forms = ReadLoginDB(test_encrypted_login_db_file_path(), true);
+    EXPECT_TRUE(stored_forms.empty());
+    EXPECT_THAT(migration_step_pref_.GetValue(), PasswordStoreX::POSTPONED);
+  } else {  // NO_BACKEND
     // No values should be moved without a working backend.
     auto stored_forms = ReadLoginDB(test_encrypted_login_db_file_path(), true);
     EXPECT_TRUE(stored_forms.empty());

components/password_manager/core/browser/password_manager_metrics_util.h

@@ -287,7 +287,17 @@ enum class LinuxBackendMigrationStatus {
   kCopiedAll = 2,
   // The standard login database is encrypted.
   kLoginDBReplaced = 3,
-  kMaxValue = kLoginDBReplaced
+  // The migration is about to be attempted.
+  kStarted = 4,
+  // No access to the native backend.
+  kPostponed = 5,
+  // Could not create or write into the temporary file.
+  kFailedCreatedEncrypted = 6,
+  // Could not read from the native backend.
+  kFailedAccessNative = 7,
+  // Could not replace old database.
+  kFailedReplace = 8,
+  kMaxValue = kFailedReplace
 };
 
 // Type of the password drop-down shown on focus field.

tools/metrics/histograms/enums.xml

@@ -28769,6 +28769,11 @@ Called by update_gpu_driver_bug_workaround_entries.py.-->
   <int value="1" label="Failed"/>
   <int value="2" label="Copied everything"/>
   <int value="3" label="The standard login database is encrypted"/>
+  <int value="4" label="The migration is about to be attempted"/>
+  <int value="5" label="No access to the native backend"/>
+  <int value="6" label="Could not create or write into the temporary file"/>
+  <int value="7" label="Could not read from the native backend"/>
+  <int value="8" label="Could not replace old database"/>
 </enum>
 
 <enum name="LinuxSandboxStatus">