Convert sql_unittests 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 95ad1b27bea4c420f0ab6aff7c6b7e083d591af8..97b751031cd62aaf2e47525732558ebfdc76cbb3 100644
--- a/testing/buildbot/chromium.linux.json
+++ b/testing/buildbot/chromium.linux.json
@@ -184,6 +184,9 @@
         "test": "sandbox_linux_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "sql_unittests"
       },
       {
@@ -679,6 +682,9 @@
         "test": "skia_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "sql_unittests"
       },
       {
@@ -966,6 +972,9 @@
         "test": "skia_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "sql_unittests"
       },
       {
@@ -1237,6 +1246,9 @@
         "test": "skia_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "sql_unittests"
       },
       {