Specify chromium.tests.robocrop pool dimension for Linux Tests Robocrop

Doesn't schedule Linux Tests Robocrop and Linux Builder Robocrop.
linux-rel-builder will just mirror them and trigger tests in
chromium.tests.robocrop

Bug: 1143924
Change-Id: I70dc5ddb8b9f36f4c7b15bfcfc40605b589a717d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2545646
Commit-Queue: Stephanie Kim <kimstephanie@google.com>
Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828909}

testing/buildbot/generate_buildbot_json.py

@@ -1446,6 +1446,9 @@ class BBJSONGenerator(object):
         "chromeos-kevin-chrome-lts",
         "linux-chromeos-lts",
         "linux64-lts",
+        # TODO crbug.com/1143924: Remove once experimentation is complete
+        'Linux Builder Robocrop',
+        'Linux Tests Robocrop',
     ]
 
   def get_internal_waterfalls(self):

testing/buildbot/mixins.pyl

@@ -790,6 +790,13 @@
       },
     },
   },
+  'robocrop-swarming-pool': {
+    'swarming': {
+      'dimensions': {
+        'pool': 'chromium.tests.robocrop',
+      },
+    },
+  },
   'sailfish': {
     # Pixel 1
     'swarming': {

testing/buildbot/waterfalls.pyl

@@ -4570,6 +4570,17 @@
           'sync_integration_tests'
         ]
       },
+      'Linux Builder Robocrop': {
+        'mixins': [
+          'isolate_profile_data',
+        ],
+        'additional_compile_targets': [
+          'all'
+        ],
+        'test_suites': {
+          'scripts': 'check_network_annotations_script',
+        }
+      },
       'Linux Ozone Tester (Headless)': {
         'mixins': [
           'linux-xenial',
@@ -4638,6 +4649,18 @@
           'isolated_scripts': 'chromium_linux_dbg_isolated_scripts',
         },
       },
+      'Linux Tests Robocrop': {
+        'mixins': [
+          'isolate_profile_data',
+          'linux-xenial',
+          'robocrop-swarming-pool',
+        ],
+        'test_suites': {
+          'gtest_tests': 'chromium_linux_gtests',
+          'isolated_scripts': 'chromium_linux_rel_isolated_scripts',
+          'scripts': 'chromium_linux_scripts',
+        },
+      },
       # For documentation, see //services/network/README.md.
       'Network Service Linux': {
         'mixins': [