Convert ppapi_unittests to run exclusively on Swarming

testing/buildbot/chromium.win.json

Index: testing/buildbot/chromium.win.json
diff --git a/testing/buildbot/chromium.win.json b/testing/buildbot/chromium.win.json
index b0b81434346c28dd508a2b84245229df73a15641..b1dfb69657a8734ae56a1119303aed81320c214a 100644
--- a/testing/buildbot/chromium.win.json
+++ b/testing/buildbot/chromium.win.json
@@ -193,6 +193,9 @@
         "test": "net_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ppapi_unittests"
       },
       {
@@ -503,6 +506,9 @@
         "test": "net_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ppapi_unittests"
       },
       {
@@ -932,6 +938,9 @@
         "test": "net_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ppapi_unittests"
       },
       {
@@ -1218,6 +1227,9 @@
         "test": "net_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ppapi_unittests"
       },
       {
@@ -1663,6 +1675,9 @@
         "test": "net_unittests"
       },
       {
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
         "test": "ppapi_unittests"
       },
       {