Move Win x64 clobber bot and remove Win x64 GN bots.

scripts/slave/recipe_modules/chromium_tests/chromium.py

Index: scripts/slave/recipe_modules/chromium_tests/chromium.py
diff --git a/scripts/slave/recipe_modules/chromium_tests/chromium.py b/scripts/slave/recipe_modules/chromium_tests/chromium.py
index cc6f2f386fe3c6a54209c387f52fdcce3a7350d3..010b8ffc7e169c17bcb6ce36b00d709f948adcf9 100644
--- a/scripts/slave/recipe_modules/chromium_tests/chromium.py
+++ b/scripts/slave/recipe_modules/chromium_tests/chromium.py
@@ -34,6 +34,34 @@ SPEC = {
         'platform': 'win',
       },
     },
+    'Win x64': {
+      'chromium_config': 'chromium',
+      'chromium_apply_config': [
+        'clobber',
+        'isolation_mode_noop',
+        'ninja_confirm_noop',
+        'no_dump_symbols',
+      ],
+      'gclient_config': 'chromium',
+      'chromium_config_kwargs': {
+        'BUILD_CONFIG': 'Release',
+        'TARGET_BITS': 64,
+      },
+      'compile_targets': [
+        'all',
+      ],
+      'test_generators': [
+        steps.generate_gtest,
+        steps.generate_script,
+        steps.generate_isolated_script,
+      ],
+      'archive_build': True,
+      'gs_bucket': 'chromium-browser-snapshots',
+      'gs_acl': 'public-read',
+      'testing': {
+        'platform': 'win',
+      },
+    },
     'Mac': {
       'chromium_config': 'chromium',
       'chromium_apply_config': [