[gn] Switch custom snapsot bot to gn

infra/mb/mb_config.pyl

 # Copyright 2016 The V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   # This is a map of buildbot master names -> buildbot builder names ->
   # config names (where each config name is a key in the 'configs' dict,
   # below). MB uses this dict to look up which config to use for a given bot.
   # Bots are ordered by appearance on waterfall.
   'masters': {
     'client.dart.fyi': {
       'v8-linux-release': 'gyp_release_x86_disassembler',
       'v8-win-release': 'gyp_release_x86_disassembler',
       'v8-mac-release': 'gyp_release_x86_disassembler',
     },
     'client.dynamorio': {
       'linux-v8-dr': 'gyp_release_x64',
     },
     'client.v8': {
       # Linux.
       'V8 Linux - builder': 'gyp_release_x86_gcmole',
       'V8 Linux - debug builder': 'gyp_debug_x86',
       'V8 Linux - nosnap builder': 'gyp_release_x86_no_snap',
       'V8 Linux - nosnap debug builder': 'gyp_debug_x86_no_snap',
       'V8 Linux - shared': 'gyp_release_x86_shared_verify_heap',
       'V8 Linux - noi18n - debug': 'gyp_debug_x86_no_i18n',
       # Linux64.
       'V8 Linux64 - builder': 'gn_release_x64',
       'V8 Linux64 - debug builder': 'gn_debug_x64_valgrind',
-      'V8 Linux64 - custom snapshot - debug builder': 'gyp_debug_x64_custom',
+      'V8 Linux64 - custom snapshot - debug builder': 'gn_debug_x64_custom',
       'V8 Linux64 - internal snapshot': 'gn_release_x64_internal',
       # Windows.
       'V8 Win32 - builder': 'gyp_release_x86_minimal_symbols',
       'V8 Win32 - debug builder': 'gyp_debug_x86_minimal_symbols',
       'V8 Win32 - nosnap - shared':
         'gyp_release_x86_no_snap_shared_minimal_symbols',
       'V8 Win64': 'gyp_release_x64_minimal_symbols',
       'V8 Win64 - debug': 'gyp_debug_x64_minimal_symbols',
       'V8 Win64 - clang': 'gyp_release_x64_clang',
       # Mac.
@@ skipping 138 matching lines @@
   'configs': {
     # GN release configs for x64.
     'gn_release_x64': [
       'gn', 'release_bot', 'x64', 'swarming'],
     'gn_release_x64_internal': [
       'gn', 'release_bot', 'x64', 'swarming', 'v8_snapshot_internal'],
     'gn_release_x64_trybot': [
       'gn', 'release_trybot', 'x64', 'swarming'],
 
     # GN debug configs for x64.
+    'gn_debug_x64_custom': [
+      'gn', 'debug_bot', 'x64', 'swarming', 'v8_snapshot_custom'],
     'gn_debug_x64_trybot': [
       'gn', 'debug_trybot', 'x64', 'swarming'],
     'gn_debug_x64_valgrind': [
       'gn', 'debug_bot', 'x64', 'swarming', 'valgrind'],
 
     # Gyp debug configs for arm.
     'gyp_debug_arm': [
       'gyp', 'debug_bot', 'arm', 'crosscompile', 'hard_float', 'swarming'],
 
     # Gyp debug configs for simulators.
@@ skipping 10 matching lines @@
     'gyp_debug_simulate_mipsel_asan_edge': [
       'gyp', 'debug_bot', 'simulate_mipsel', 'asan', 'edge'],
     'gyp_debug_simulate_x87_no_snap': [
       'gyp', 'debug_bot', 'simulate_x87', 'v8_snapshot_none'],
 
     # Gyp debug configs for x64.
     'gyp_debug_x64': [
       'gyp', 'debug_bot', 'x64', 'swarming'],
     'gyp_debug_x64_asan_edge': [
       'gyp', 'debug_bot', 'x64', 'asan', 'lsan', 'edge'],
-    'gyp_debug_x64_custom': [
-      'gyp', 'debug_bot', 'x64', 'swarming', 'v8_snapshot_custom'],
     'gyp_debug_x64_minimal_symbols': [
       'gyp', 'debug_bot', 'x64', 'minimal_symbols', 'swarming'],
 
     # Gyp debug configs for x86.
     'gyp_debug_x86': [
       'gyp', 'debug_bot', 'x86', 'swarming'],
     'gyp_debug_x86_minimal_symbols': [
       'gyp', 'debug_bot', 'x86', 'minimal_symbols', 'swarming'],
     'gyp_debug_x86_trybot': [
       'gyp', 'debug_trybot', 'x86', 'swarming'],
@@ skipping 351 matching lines @@
       'gn_args': 'v8_interpreted_regexp=true',
       'gyp_defines': 'v8_interpreted_regexp=1',
     },
 
     'v8_optimized_debug': {
       # This is the default in gn for debug.
       'gyp_defines': 'v8_optimized_debug=1',
     },
 
     'v8_snapshot_custom': {
-      # TODO(machenbach): Add this to gn.
-      # Path needs to be relative to src/v8.gyp.
+      # GN path is relative to project root.
+      'gn_args': 'v8_embed_script="test/mjsunit/mjsunit.js"',
+
+      # Gyp path is relative to src/v8.gyp.
       'gyp_defines': 'embed_script=../test/mjsunit/mjsunit.js',
     },
 
     'v8_snapshot_internal': {
       'gn_args': 'v8_use_external_startup_data=false',
       'gyp_defines': 'v8_use_external_startup_data=0',
     },
 
     'v8_snapshot_none': {
       'gn_args': 'v8_use_snapshot=false',
       'gyp_defines': 'v8_use_snapshot=false',
     },
 
     'v8_verify_heap': {
       'gn_args': 'v8_enable_verify_heap=true',
       'gyp_defines': 'v8_enable_verify_heap=1',
     },
 
     'x64': {
       'gn_args': 'target_cpu="x64"',
       'gyp_defines': 'target_arch=x64',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
       'gyp_defines': 'target_arch=ia32',
     },
   },
 }