[debugger] remove frame argument for prepare step.

test/mjsunit/mjsunit.status

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 13 matching lines @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 [
 [ALWAYS, {
   # All tests in the bug directory are expected to fail.
   'bugs/*': [FAIL],
 
   ##############################################################################
-  # Flaky tests.
-  # BUG(v8:2921).
-  'debug-step-4-in-frame': [PASS, FAIL, SLOW],
-
-  ##############################################################################
   # Fails.
   'regress/regress-1119': [FAIL],
 
   # Issue 1719: Slow to collect arrays over several contexts.
   'regress/regress-524': [SKIP],
   # When that bug is fixed, revert the expectation to:
   # Skip long running test in debug and allow it to timeout in release mode.
   # regress/regress-524: [PASS, TIMEOUT, ['mode == debug', SKIP]],
 
   # This test non-deterministically runs out of memory on Windows ia32.
@@ skipping 1028 matching lines @@
 
 ##############################################################################
 ['gcov_coverage', {
   # Tests taking too long.
   'array-functions-prototype-misc': [SKIP],
   'strong/implicit-conversions': [SKIP],
   'strong/load-element-mutate-backing-store': [SKIP],
 }],  # 'gcov_coverage'
 
 ]