--- a/toolkit/components/telemetry/tests/unit/test_ChildHistograms.js
+++ b/toolkit/components/telemetry/tests/unit/test_ChildHistograms.js
@@ -1,12 +1,13 @@
 
 Cu.import("resource://gre/modules/TelemetryController.jsm", this);
 Cu.import("resource://gre/modules/TelemetrySession.jsm", this);
 Cu.import("resource://gre/modules/PromiseUtils.jsm", this);
+Cu.import("resource://testing-common/ContentTaskUtils.jsm", this);
 
 const MESSAGE_TELEMETRY_PAYLOAD = "Telemetry:Payload";
 const MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD = "Telemetry:GetChildPayload";
 const MESSAGE_CHILD_TEST_DONE = "ChildTest:Done";
 
 const PLATFORM_VERSION = "1.9.2";
 const APP_VERSION = "1";
 const APP_ID = "xpcshell@tests.mozilla.org";
@@ -22,20 +23,16 @@ function run_child_test() {
 
   let flagKeyed = Telemetry.getKeyedHistogramById("TELEMETRY_TEST_KEYED_FLAG");
   flagKeyed.add("a", 1);
   flagKeyed.add("b", 1);
   let countKeyed = Telemetry.getKeyedHistogramById("TELEMETRY_TEST_KEYED_COUNT");
   countKeyed.add("a");
   countKeyed.add("b");
   countKeyed.add("b");
-
-  // Check payload values.
-  const payload = TelemetrySession.getPayload("test-ping");
-  check_histogram_values(payload);
 }
 
 function check_histogram_values(payload) {
   const hs = payload.histograms;
   Assert.ok("TELEMETRY_TEST_COUNT" in hs, "Should have count test histogram.");
   Assert.ok("TELEMETRY_TEST_FLAG" in hs, "Should have flag test histogram.");
   Assert.equal(hs["TELEMETRY_TEST_COUNT"].sum, 2,
                "Count test histogram should have the right value.");
@@ -56,18 +53,16 @@ function check_histogram_values(payload)
 }
 
 add_task(function*() {
   if (!runningInParent) {
     TelemetryController.testSetupContent();
     run_child_test();
     dump("... done with child test\n");
     do_send_remote_message(MESSAGE_CHILD_TEST_DONE);
-    dump("... waiting for child payload collection\n");
-    yield do_await_remote_message(MESSAGE_TELEMETRY_GET_CHILD_PAYLOAD);
     return;
   }
 
   // Setup.
   do_get_profile(true);
   loadAddonManager(APP_ID, APP_NAME, APP_VERSION, PLATFORM_VERSION);
   Services.prefs.setBoolPref(PREF_TELEMETRY_ENABLED, true);
   yield TelemetryController.testSetup();
@@ -75,25 +70,25 @@ add_task(function*() {
     // Make sure we don't generate unexpected pings due to pref changes.
     yield setEmptyPrefWatchlist();
   }
 
   // Run test in child, don't wait for it to finish.
   let childPromise = run_test_in_child("test_ChildHistograms.js");
   yield do_await_remote_message(MESSAGE_CHILD_TEST_DONE);
 
-  // Gather payload from child.
-  dump("... requesting child payloads\n");
-  let promiseMessage = do_await_remote_message(MESSAGE_TELEMETRY_PAYLOAD);
-  TelemetrySession.requestChildPayloads();
-  yield promiseMessage;
-  dump("... received child payload\n");
-
-  // Check child payload.
+  yield ContentTaskUtils.waitForCondition(() => {
+    let payload = TelemetrySession.getPayload("test-ping");
+    return payload &&
+           "processes" in payload &&
+           "content" in payload.processes &&
+           "histograms" in payload.processes.content &&
+           "TELEMETRY_TEST_COUNT" in payload.processes.content.histograms;
+  });
   const payload = TelemetrySession.getPayload("test-ping");
-  Assert.ok("childPayloads" in payload, "Should have child payloads.");
-  Assert.equal(payload.childPayloads.length, 1, "Should have received one child payload so far.");
-  Assert.ok("histograms" in payload.childPayloads[0], "Child payload should have histograms.");
-  Assert.ok("keyedHistograms" in payload.childPayloads[0], "Child payload should have keyed histograms.");
-  check_histogram_values(payload.childPayloads[0]);
+  Assert.ok("processes" in payload, "Should have processes section");
+  Assert.ok("content" in payload.processes,"Should have child process section");
+  Assert.ok("histograms" in payload.processes.content, "Child process section should have histograms.");
+  Assert.ok("keyedHistograms" in payload.processes.content, "Child process section should have keyed histograms.");
+  check_histogram_values(payload.processes.content);
 
   do_test_finished();
 });