Bug 1638138 - Restoring missing thread names in requestProcInfo;r=tarek

ChromeUtils::requestProcInfo was dropping thread names for the process process. This patch restores them and tests that at least *one* thread is named. Unfortunately, at the time of this writing, we cannot assume that *all*
threads are named. Investigation pending.

Differential Revision: https://phabricator.services.mozilla.com/D75420

dom/base/ChromeUtils.cpp

@@ -946,6 +946,7 @@ already_AddRefed<Promise> ChromeUtils::RequestProcInfo(GlobalObject& aGlobal,
                     thread->mCpuUser = entry.cpuUser;
                     thread->mCpuKernel = entry.cpuKernel;
                     thread->mTid = entry.tid;
+                    thread->mName.Assign(entry.name);
                   }
                   procInfo.mThreads = std::move(threads);
 

widget/tests/browser/browser_test_procinfo.js

@@ -31,6 +31,11 @@ add_task(async function test_proc_info() {
           cpuThreads += parentProc.threads[x].cpuUser;
         }
 
+        Assert.ok(
+          parentProc.threads.some(thread => thread.name),
+          "At least one of the threads of the parent process is named"
+        );
+
         for (var i = 0; i < parentProc.children.length; i++) {
           let childProc = parentProc.children[i];
           Assert.notEqual(