sql: Remove redundant PRAGMA secure_delete=ON.

Chrome builds SQLite with SQLITE_SECURE_DELETE [1], so the default value
for the secure_delete PRAGMA [2] is already true.

[1] https://www.sqlite.org/compile.html#secure_delete
[2] https://www.sqlite.org/pragma.html#pragma_secure_delete

Bug: 910955
Change-Id: I27ef32770a980c8c6030675e79698d7a31e47a9d
Reviewed-on: https://chromium-review.googlesource.com/c/1357824
Commit-Queue: Victor Costan <pwnall@chromium.org>
Reviewed-by: Chris Mumford <cmumford@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613866}

sql/database.cc

@@ -1663,8 +1663,8 @@ bool Database::OpenInternal(const std::string& file_name,
     OnSqliteError(err, nullptr, "PRAGMA auto_vacuum");
 
     // Retry or bail out if the error handler poisoned the handle.
-    // TODO(shess): Move this handling to one place (see also sqlite3_open and
-    // secure_delete).  Possibly a wrapper function?
+    // TODO(shess): Move this handling to one place (see also sqlite3_open).
+    //              Possibly a wrapper function?
     if (poisoned_) {
       Close();
       if (retry_flag == RETRY_ON_POISON)
@@ -1715,13 +1715,8 @@ bool Database::OpenInternal(const std::string& file_name,
     ignore_result(ExecuteWithTimeout(cache_size_sql.c_str(), kBusyTimeout));
   }
 
-  if (!ExecuteWithTimeout("PRAGMA secure_delete=ON", kBusyTimeout)) {
-    bool was_poisoned = poisoned_;
-    Close();
-    if (was_poisoned && retry_flag == RETRY_ON_POISON)
-      return OpenInternal(file_name, NO_RETRY);
-    return false;
-  }
+  static_assert(SQLITE_SECURE_DELETE == 1,
+                "Chrome assumes secure_delete is on by default.");
 
   // Set a reasonable chunk size for larger files.  This reduces churn from
   // remapping memory on size changes.  It also reduces filesystem

third_party/blink/web_tests/storage/websql/test-authorizer-expected.txt

@@ -22,7 +22,7 @@ SQLITE_TRANSACTION statement failed: could not prepare statement (23 not authori
 SQLITE_ATTACH statement failed: could not prepare statement (23 not authorized)
 SQLITE_DETACH statement failed: could not prepare statement (23 not authorized)
 SQLITE_REINDEX statement failed: could not prepare statement (1 near "REINDEX": syntax error)
-SQLITE_ANALYZE statement failed: could not prepare statement (23 not authorized)
+SQLITE_ANALYZE statement failed: could not prepare statement (1 near "ANALYZE": syntax error)
 SQLITE_DROP_INDEX statement succeeded.
 SQLITE_DROP_TEMP_TABLE statement succeeded.
 SQLITE_DROP_TEMP_TRIGGER statement succeeded.
@@ -61,7 +61,7 @@ SQLITE_TRANSACTION statement failed: could not prepare statement (23 not authori
 SQLITE_ATTACH statement failed: could not prepare statement (23 not authorized)
 SQLITE_DETACH statement failed: could not prepare statement (23 not authorized)
 SQLITE_REINDEX statement failed: could not prepare statement (1 near "REINDEX": syntax error)
-SQLITE_ANALYZE statement failed: could not prepare statement (23 not authorized)
+SQLITE_ANALYZE statement failed: could not prepare statement (1 near "ANALYZE": syntax error)
 SQLITE_DROP_INDEX statement failed: could not prepare statement (23 not authorized)
 SQLITE_DROP_TEMP_TABLE statement failed: could not prepare statement (23 not authorized)
 SQLITE_DROP_TEMP_TRIGGER statement failed: could not prepare statement (23 not authorized)

third_party/sqlite/BUILD.gn

@@ -90,6 +90,17 @@ config("chromium_sqlite3_compile_options") {
     "SQLITE_OMIT_SHARED_CACHE",
     "SQLITE_USE_ALLOCA",
 
+    # Chrome doesn't use the ANALYZE SQLite extension.
+    #
+    # ANALYZE [1] is non-standard, and currently performs a table scan to
+    # update statistics used by the query planner. Chrome uses straightforward
+    # database schemas which do not require the level of fine tuning provided
+    # by ANALYZE, and we generally cannot afford the I/O cost of the required
+    # table scans.
+    #
+    # [1] https://www.sqlite.org/lang_analyze.html
+    "SQLITE_OMIT_ANALYZE",
+
     # Chrome initializes SQLite manually in //sql/connection.cc.
     "SQLITE_OMIT_AUTOINIT",