2 files changed, 65 insertions, 0 deletions
diff --git a/testing/web-platform/tests/compute-pressure/resources/pressure-helpers.js b/testing/web-platform/tests/compute-pressure/resources/pressure-helpers.js
new file mode 100644
index 0000000000..5234cf2d78
--- /dev/null
+++ b/testing/web-platform/tests/compute-pressure/resources/pressure-helpers.js
@@ -0,0 +1,35 @@
+'use strict';
+
+// These tests rely on the User Agent providing an implementation of
+// platform compute pressure backends.
+//
+// In Chromium-based browsers this implementation is provided by a polyfill
+// in order to reduce the amount of test-only code shipped to users. To enable
+// these tests the browser must be run with these options:
+//
+//   --enable-blink-features=MojoJS,MojoJSTest
+
+let mockPressureService = undefined;
+
+function pressure_test(func, name, properties) {
+  promise_test(async t => {
+    if (mockPressureService === undefined) {
+      if (isChromiumBased) {
+        const mocks =
+            await import('/resources/chromium/mock-pressure-service.js');
+        mockPressureService = mocks.mockPressureService;
+      }
+    }
+    assert_implements(
+        mockPressureService,
+        'missing mockPressureService after initialization');
+
+    mockPressureService.start();
+
+    t.add_cleanup(() => {
+      mockPressureService.reset();
+      return mockPressureService.stop();
+    });
+    return func(t, mockPressureService);
+  }, name, properties);
+}
diff --git a/testing/web-platform/tests/compute-pressure/resources/support-iframe.html b/testing/web-platform/tests/compute-pressure/resources/support-iframe.html
new file mode 100644
index 0000000000..57e18b77f6
--- /dev/null
+++ b/testing/web-platform/tests/compute-pressure/resources/support-iframe.html
@@ -0,0 +1,30 @@
+<!DOCTYPE HTML>
+<meta charset="utf-8">
+<title>compute pressure iframe tester</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+async function messageHandler(e) {
+  if (e.data.command === 'start') {
+    return new Promise((resolve, reject) => {
+        const observer = new PressureObserver(()=> {
+            resolve('success');
+        });
+        observer.observe('cpu');
+        window.setTimeout(() => { reject('timeout'); }, 2000);
+    });
+  } else {
+    return Promise.reject(`unknown command "${e.data.command}"`);
+  }
+}
+
+window.onmessage = async (e) => {
+  let reply;
+  try {
+    reply = await messageHandler(e);
+  } catch (error) {
+    reply = error;
+  }
+  e.source.postMessage({ command: e.data.command, result: reply }, '*');
+}
+</script>