Convert wm_unittests to run exclusively on Swarming

testing/buildbot/chromium.memory.fyi.json

 {
   "Linux ChromeOS MSan Tests": {
     "gtest_tests": [
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "accessibility_unittests"
       },
       {
@@ skipping 223 matching lines @@
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "url_unittests"
       },
       {
         "test": "views_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "wm_unittests"
       }
     ]
   },
   "Linux MSan Tests": {
     "gtest_tests": [
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
@@ skipping 237 matching lines @@
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "url_unittests"
       },
       {
         "test": "views_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "wm_unittests"
       }
     ]
   },
   "Linux TSan Tests": {
     "disabled_tests": {
       "app_shell_browsertests": "http://crbug.com/455633",
       "browser_tests": "Too many errors, clean content_browsertests first. http://crbug.com/368525",
       "cc_unittests": "http://crbug.com/437454",
       "interactive_ui_tests": "http://crbug.com/455679"
@@ skipping 199 matching lines @@
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "url_unittests"
       },
       {
         "test": "views_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "wm_unittests"
       }
     ]
   }
 }