sql: Remove unused iOS-specific header in sql/connection_unittest.cc

After https://crrev.com/c/898564, //base/ios/ios_util.h is not needed by
SQL::Connection unittests.

Bug: 807093
Change-Id: If6736c69dc42d35ecc24a01fc19d43d04b5db7d8
Reviewed-on: https://chromium-review.googlesource.com/903585
Reviewed-by: Chris Mumford <cmumford@chromium.org>
Commit-Queue: Victor Costan <pwnall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534772}

sql/connection_unittest.cc

@@ -26,10 +26,6 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/sqlite/sqlite3.h"
 
-#if defined(OS_IOS) && defined(USE_SYSTEM_SQLITE)
-#include "base/ios/ios_util.h"
-#endif  // defined(OS_IOS) && defined(USE_SYSTEM_SQLITE)
-
 namespace sql {
 namespace test {