Convert ipc_tests to run exclusively on Swarming

testing/buildbot/chromium.linux.json

Index: testing/buildbot/chromium.linux.json
diff --git a/testing/buildbot/chromium.linux.json b/testing/buildbot/chromium.linux.json
index d1552e14577a32fcf08c56b5b03ec89ff6b86cb1..07a0ab00cd50bc97db501c198193883e773e276e 100644
--- a/testing/buildbot/chromium.linux.json
+++ b/testing/buildbot/chromium.linux.json
@@ -139,6 +139,9 @@
         "test": "gpu_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ipc_tests"
       },
       {
@@ -586,6 +589,9 @@
         "test": "ipc_mojo_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ipc_tests"
       },
       {
@@ -852,6 +858,9 @@
         "test": "ipc_mojo_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ipc_tests"
       },
       {
@@ -1108,6 +1117,9 @@
         "test": "ipc_mojo_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ipc_tests"
       },
       {