[sql] Track SQLite error codes from sql::Recovery ATTACH.

sql/recovery_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sql/recovery.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/test/histogram_tester.h"
 #include "sql/connection.h"
 #include "sql/meta_table.h"
 #include "sql/statement.h"
 #include "sql/test/paths.h"
 #include "sql/test/scoped_error_expecter.h"
 #include "sql/test/sql_test_base.h"
 #include "sql/test/test_helpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/sqlite/sqlite3.h"
 
@@ skipping 796 matching lines @@
 
   // Test that the trigger works.
   ASSERT_TRUE(db().Execute("DELETE FROM x WHERE v = 'truck'"));
   EXPECT_EQ("1|turtle\n3|trailer",
             ExecuteWithResults(&db(), kXSql, "|", "\n"));
   EXPECT_EQ("dean|trailer\njim|telephone",
             ExecuteWithResults(&db(), kYSql, "|", "\n"));
   EXPECT_EQ("trailer", ExecuteWithResults(&db(), kVSql, "|", "\n"));
 }
 
+// Test histograms recorded when the invalid database cannot be attached.
+TEST_F(SQLRecoveryTest, AttachFailure) {
+  // Create a valid database, then write junk over the header.  This should lead
+  // to SQLITE_NOTADB, which will cause ATTACH to fail.
+  ASSERT_TRUE(db().Execute("CREATE TABLE x (t TEXT)"));
+  ASSERT_TRUE(db().Execute("INSERT INTO x VALUES ('This is a test')"));
+  db().Close();
+  WriteJunkToDatabase(SQLTestBase::TYPE_OVERWRITE);
+
+  const char kEventHistogramName[] = "Sqlite.RecoveryEvents";
+  const int kEventEnum = 5;  // RECOVERY_FAILED_ATTACH
+  const char kErrorHistogramName[] = "Sqlite.RecoveryAttachError";
+  base::HistogramTester tester;
+
+  {
+    sql::test::ScopedErrorExpecter expecter;
+    expecter.ExpectError(SQLITE_NOTADB);
+
+    // Reopen() here because it will see SQLITE_NOTADB.
+    ASSERT_TRUE(Reopen());
+
+    // Begin() should fail.
+    std::unique_ptr<sql::Recovery>
+        recovery = sql::Recovery::Begin(&db(), db_path());
+    ASSERT_FALSE(recovery.get());
+
+    ASSERT_TRUE(expecter.SawExpectedErrors());
+  }
+
+  // Verify that the failure was in the right place with the expected code.
+  tester.ExpectBucketCount(kEventHistogramName, kEventEnum, 1);
+  tester.ExpectBucketCount(kErrorHistogramName, SQLITE_NOTADB, 1);
+}
+
 }  // namespace