[ComputePressure] Improve implementation of focus control

This CL improves implementation of focus control in two ways:
1. Check if FocusController is focused. This can resolve the bug that
page not in focus still gets update.
2. Remove IsOutermostMainFrame() check. As discussed in [1], this is
not the necessary condition.

[1] w3c/compute-pressure#185

Bug: 1403458
Change-Id: I65186b7bd01438ca0c2e5b7e8a09355b5704f8d5

compute-pressure/compute_pressure_privacy_test.tentative.https.window.js

@@ -8,6 +8,39 @@
 
 'use strict';
 
+promise_test(async t => {
+  const iframe = document.createElement('iframe');
+  document.body.appendChild(iframe);
+  iframe.contentWindow.focus();
+
+  await new Promise(resolve => {
+    const observer = new PressureObserver(resolve);
+    t.add_cleanup(async () => {
+      observer.disconnect();
+      iframe.remove();
+    });
+    observer.observe('cpu');
+  });
+}, 'Observer in main frame should receive PressureRecord when focused on same-origin iframe');
+
+promise_test(async t => {
+  const iframe = document.createElement('iframe');
+  iframe.src = get_host_info().HTTPS_REMOTE_ORIGIN +
+      '/compute-pressure/resources/support-iframe.html';
+  document.body.appendChild(iframe);
+  iframe.contentWindow.focus();
+
+  const observer = new PressureObserver(() => {
+    assert_unreached('The observer callback should not be called');
+  });
+  t.add_cleanup(() => {
+    observer.disconnect();
+    iframe.remove();
+  });
+
+  return new Promise(resolve => t.step_timeout(resolve, 2000));
+}, 'Observer in main frame should not receive PressureRecord when focused on cross-origin iframe');
+
 promise_test(async t => {
   const video = await loadVideo();
   document.body.appendChild(video);
@@ -16,12 +49,13 @@ promise_test(async t => {
   assert_not_equals(pipWindow.height, 0);
 
   const iframe = document.createElement('iframe');
+  iframe.src = get_host_info().HTTPS_REMOTE_ORIGIN +
+      '/compute-pressure/resources/support-iframe.html';
   document.body.appendChild(iframe);
-  // Focus on the iframe to make the main frame lose focus, so that
-  // PressureObserver in the main frame can't receive PressureRecord
-  // by default. However, if the main frame is the initiator of active
-  // Picture-in-Picture session, PressureObserver in the main frame can
-  // receive PressureRecord.
+  // Focus on the cross-origin iframe, so that PressureObserver in the main
+  // frame can't receive PressureRecord by default. However, if the main
+  // frame is the initiator of active Picture-in-Picture session,
+  // PressureObserver in the main frame can receive PressureRecord.
   iframe.contentWindow.focus();
 
   await new Promise(resolve => {
@@ -45,11 +79,13 @@ promise_test(async t => {
   assert_true(stream.active);
 
   const iframe = document.createElement('iframe');
+  iframe.src = get_host_info().HTTPS_REMOTE_ORIGIN +
+      '/compute-pressure/resources/support-iframe.html';
   document.body.appendChild(iframe);
-  // Focus on the iframe to make the main frame lose focus, so that
-  // PressureObserver in the main frame can't receive PressureRecord
-  // by default. However, if the main frame's browsing context is capturing,
-  // PressureObserver in the main frame can receive PressureRecord.
+  // Focus on the cross-origin iframe, so that PressureObserver in the main
+  // frame can't receive PressureRecord by default. However, if the main
+  // frame's browsing context is capturing, PressureObserver in the main
+  // frame can receive PressureRecord.
   iframe.contentWindow.focus();
 
   await new Promise(resolve => {
@@ -63,25 +99,6 @@ promise_test(async t => {
   });
 }, 'Observer should receive PressureRecord if browsing context is capturing');
 
-promise_test(async t => {
-  const iframe = document.createElement('iframe');
-  document.body.appendChild(iframe);
-  // Focus on the iframe to make the main frame lose focus, so that
-  // PressureObserver in the main frame can't receive PressureRecord
-  // by default.
-  iframe.contentWindow.focus();
-
-  const observer = new PressureObserver(() => {
-    assert_unreached('The observer callback should not be called');
-  });
-  t.add_cleanup(() => {
-    observer.disconnect();
-    iframe.remove();
-  });
-
-  return new Promise(resolve => t.step_timeout(resolve, 2000));
-}, 'Observer should not receive PressureRecord when top-level browsing context does not have system focus');
-
 promise_test(async t => {
   const iframe = document.createElement('iframe');
   document.body.appendChild(iframe);