Bug 1301340 - part4: Force single content process for failing tests. r=mrbkap

devtools/client/aboutdebugging/test/browser_service_workers_status.js

@@ -18,6 +18,7 @@ add_task(function* () {
       ["dom.serviceWorkers.testing.enabled", true],
       ["dom.serviceWorkers.idle_timeout", SW_TIMEOUT],
       ["dom.serviceWorkers.idle_extended_timeout", SW_TIMEOUT],
+      ["dom.ipc.processCount", 1],
     ]
   });
 

devtools/client/aboutdebugging/test/browser_service_workers_unregister.js

@@ -20,6 +20,7 @@ add_task(function* () {
     let options = { "set": [
       // Accept workers from mochitest's http.
       ["dom.serviceWorkers.testing.enabled", true],
+      ["dom.ipc.processCount", 1],
     ]};
     SpecialPowers.pushPrefEnv(options, done);
   });

devtools/client/aboutdebugging/test/browser_tabs.js

@@ -5,6 +5,12 @@
 
 const TAB_URL = "data:text/html,<title>foo</title>";
 
+add_task(function* setup() {
+  yield SpecialPowers.pushPrefEnv({
+    set: [["dom.ipc.processCount", 1]]
+  });
+});
+
 add_task(function* () {
   let { tab, document } = yield openAboutDebugging("tabs");