Reland of [gn] Switch more linux32 bots to gn (patchset #1 id:1 of...

Reland of [gn] Switch more linux32 bots to gn (patchset #1 id:1 of https://codereview.chromium.org/2128493002/ )

Reason for revert:
Should be fixed after https://codereview.chromium.org/2123223002/

Original issue's description:
> Revert of [gn] Switch more linux32 bots to gn (patchset #3 id:40001 of https://codereview.chromium.org/2122933002/ )
>
> Reason for revert:
> Breaks test isolation on shared library bot.
>
> Original issue's description:
> > [gn] Switch more linux32 bots to gn
> >
> > This switches nosnap and shared library bots to gn.
> >
> > This also unsets external startup data if no snapshot is
> > used.
> >
> > BUG=chromium:474921
> > NOTRY=true
> >
> > Committed: https://crrev.com/ab4d8fc07d9d35e6fc129098f42aa0317a02244a
> > Cr-Commit-Position: refs/heads/master@{#37546}
>
> TBR=vogelheim@chromium.org,jochen@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:474921
>
> Committed: https://crrev.com/a5fa2984257a50ee9440914c7d1a199f64a86194
> Cr-Commit-Position: refs/heads/master@{#37548}

TBR=vogelheim@chromium.org,jochen@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:474921

Review-Url: https://codereview.chromium.org/2126843002
Cr-Commit-Position: refs/heads/master@{#37558}

gni/v8.gni

@@ -22,7 +22,13 @@ declare_args() {
 
   # Use external files for startup data blobs:
   # the JS builtins sources and the start snapshot.
-  v8_use_external_startup_data = !is_ios
+  v8_use_external_startup_data = ""
+}
+
+if (v8_use_external_startup_data == "") {
+  # If not specified as a gn arg, use external startup data by default if
+  # a snapshot is used and if we're not on ios.
+  v8_use_external_startup_data = v8_use_snapshot && !is_ios
 }
 
 ###############################################################################

infra/mb/mb_config.pyl

@@ -20,9 +20,9 @@
       # Linux.
       'V8 Linux - builder': 'gn_release_x86_gcmole',
       'V8 Linux - debug builder': 'gn_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 - nosnap builder': 'gn_release_x86_no_snap',
+      'V8 Linux - nosnap debug builder': 'gn_debug_x86_no_snap',
+      'V8 Linux - shared': 'gn_release_x86_shared_verify_heap',
       'V8 Linux - noi18n - debug': 'gyp_debug_x86_no_i18n',
       # Linux64.
       'V8 Linux64 - builder': 'gn_release_x64',
@@ -135,8 +135,8 @@
       'v8_linux_dbg_ng': 'gn_debug_x86_trybot',
       'v8_linux_noi18n_rel_ng': 'gyp_release_x86_no_i18n_trybot',
       'v8_linux_gc_stress_dbg': 'gyp_debug_x86_trybot',
-      'v8_linux_nosnap_rel': 'gyp_release_x86_no_snap_trybot',
-      'v8_linux_nosnap_dbg': 'gyp_debug_x86_no_snap_trybot',
+      'v8_linux_nosnap_rel': 'gn_release_x86_no_snap_trybot',
+      'v8_linux_nosnap_dbg': 'gn_debug_x86_no_snap_trybot',
       'v8_linux_gcc_compile_rel': 'gyp_release_x86_gcc_minimal_symbols',
       'v8_linux_gcc_rel': 'gyp_release_x86_gcc_minimal_symbols',
       'v8_linux64_rel_ng': 'gn_release_x64_trybot',
@@ -196,6 +196,10 @@
     # GN debug configs for x86.
     'gn_debug_x86': [
       'gn', 'debug_bot', 'x86', 'swarming'],
+    'gn_debug_x86_no_snap': [
+      'gn', 'debug_bot', 'x86', 'swarming', 'v8_snapshot_none'],
+    'gn_debug_x86_no_snap_trybot': [
+      'gn', 'debug_trybot', 'x86', 'swarming', 'v8_snapshot_none'],
     'gn_debug_x86_trybot': [
       'gn', 'debug_trybot', 'x86', 'swarming'],
 
@@ -206,6 +210,12 @@
       'gn', 'release_trybot', 'x86', 'gcmole', 'swarming'],
     'gn_release_x86_minimal_symbols': [
       'gn', 'release_bot', 'x86', 'minimal_symbols', 'swarming'],
+    'gn_release_x86_no_snap': [
+      'gn', 'release_bot', 'x86', 'swarming', 'v8_snapshot_none'],
+    'gn_release_x86_no_snap_trybot': [
+      'gn', 'release_trybot', 'x86', 'swarming', 'v8_snapshot_none'],
+    'gn_release_x86_shared_verify_heap': [
+      'gn', 'release', 'x86', 'goma', 'shared', 'swarming', 'v8_verify_heap'],
 
     # Gyp debug configs for arm.
     'gyp_debug_arm': [
@@ -244,10 +254,6 @@
       'gyp', 'debug_trybot', 'x86', 'swarming'],
     'gyp_debug_x86_no_i18n': [
       'gyp', 'debug_bot', 'x86', 'v8_no_i18n'],
-    'gyp_debug_x86_no_snap': [
-      'gyp', 'debug_bot', 'x86', 'swarming', 'v8_snapshot_none'],
-    'gyp_debug_x86_no_snap_trybot': [
-      'gyp', 'debug_trybot', 'x86', 'swarming', 'v8_snapshot_none'],
     'gyp_debug_x86_vtunejit': [
       'gyp', 'debug_bot', 'x86', 'v8_enable_vtunejit'],
     'gyp_full_debug_x86': [
@@ -338,17 +344,11 @@
       'gyp', 'release_bot', 'x86', 'minimal_symbols', 'swarming'],
     'gyp_release_x86_no_i18n_trybot': [
       'gyp', 'release_trybot', 'x86', 'swarming', 'v8_no_i18n'],
-    'gyp_release_x86_no_snap': [
-      'gyp', 'release_bot', 'x86', 'swarming', 'v8_snapshot_none'],
     'gyp_release_x86_no_snap_shared_minimal_symbols': [
       'gyp', 'release', 'x86', 'goma', 'minimal_symbols', 'shared', 'swarming',
       'v8_snapshot_none'],
-    'gyp_release_x86_no_snap_trybot': [
-      'gyp', 'release_trybot', 'x86', 'swarming', 'v8_snapshot_none'],
     'gyp_release_x86_predictable': [
       'gyp', 'release_bot', 'x86', 'v8_enable_verify_predictable'],
-    'gyp_release_x86_shared_verify_heap': [
-      'gyp', 'release', 'x86', 'goma', 'shared', 'swarming', 'v8_verify_heap'],
     'gyp_release_x86_trybot': [
       'gyp', 'release_trybot', 'x86', 'swarming'],
   },