Convert chrome_elf_unittests to run exclusively on Swarming

testing/buildbot/chromium.fyi.json

Index: testing/buildbot/chromium.fyi.json
diff --git a/testing/buildbot/chromium.fyi.json b/testing/buildbot/chromium.fyi.json
index 1b928fcbda658cbe75822fd08fdcd1971e762b97..4f8a0a43d842370a2ef9fc43b434539ecb1e5eb6 100644
--- a/testing/buildbot/chromium.fyi.json
+++ b/testing/buildbot/chromium.fyi.json
@@ -804,6 +804,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -2225,6 +2228,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -2464,6 +2470,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -2703,6 +2712,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -2942,6 +2954,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -3181,6 +3196,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -3420,6 +3438,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -3647,6 +3668,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -3862,6 +3886,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -4070,6 +4097,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -4285,6 +4315,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -4524,6 +4557,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -4763,6 +4799,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -5002,6 +5041,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -5241,6 +5283,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -5480,6 +5525,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {
@@ -5719,6 +5767,9 @@
         "test": "chrome_app_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "chrome_elf_unittests"
       },
       {