Update blimp build bot args match build/args/blimp_engine.gn

Reorder args so it's easier to spot differences.

Remove gyp_defines because blimp is not designed to build with gyp.

BUG=602696

Committed: https://crrev.com/55bf089c901fb38204b642edc847b6259697ee9e
Cr-Commit-Position: refs/heads/master@{#386760}

Review URL: https://codereview.chromium.org/1878273003

Cr-Commit-Position: refs/heads/master@{#387010}

build/args/blimp_engine.gn

@@ -6,6 +6,9 @@
 # gn gen out/foo
 #
 # Use gn args to add your own build preference args.
+#
+# This list must be kept in sync with the blimp list in
+# //tools/mb/mb_config.pyl.
 
 use_aura = true
 use_ozone = true

tools/mb/mb_config.pyl

@@ -1567,11 +1567,14 @@
     # Removes dependencies on X11 and audio libraries for a containerized
     # build.
     'blimp': {
-      'gn_args': ('use_aura=true use_ozone=true use_alsa=false '
-                  'use_pulseaudio=false use_cups=false use_glib=false '
-                  'use_low_quality_image_interpolation=true'),
-      'gyp_defines': ('use_aura=1 use_ozone=1 use_alsa=0 '
-                      'use_pulseaudio=0 use_cups=0 use_glib=0'),
+      # This list must be kept in sync with the list in
+      # //build/args/blimp_engine.gn.
+      'gn_args': ('use_aura=true use_ozone=true ozone_auto_platforms=false '
+                  'ozone_platform="headless" ozone_platform_headless=true '
+                  'metrics_use_blimp=true '
+                  'use_low_quality_image_interpolation=true use_alsa=false '
+                  'use_pulseaudio=false use_cups=false use_glib=false'),
+      'gyp_defines': 'target_arch=unknown',
     },
 
     'cast': {