GCC: replace sequence_checker.h __has_feature with HAS_FEATURE

__has_feature is not available in GCC (and that is the reason why
we have HAS_FEATURE macro). So use HAS_FEATURE instead.

BUG=chromium:819294

Change-Id: I41923ff93a69107b160a5f1a5eb4c3056d53300d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1554666
Commit-Queue: José Dapena Paz <jose.dapena@lge.com>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#648741}

base/sequence_checker.h

@@ -55,7 +55,7 @@
   DCHECK((name).CalledOnValidSequence())
 #define DETACH_FROM_SEQUENCE(name) (name).DetachFromSequence()
 #else  // DCHECK_IS_ON()
-#if __OBJC__ && defined(OS_IOS) && !__has_feature(objc_cxx_static_assert)
+#if __OBJC__ && defined(OS_IOS) && !HAS_FEATURE(objc_cxx_static_assert)
 // TODO(thakis): Remove this branch once Xcode's clang has clang r356148.
 #define SEQUENCE_CHECKER(name)
 #else