Reland "[shared storage] Implement sharedStorage.batchUpdate() for PA…

… worklet"

This is a reland of commit f0cab8e2346b2a62aa3be1d5a41ec7737bf335af

The original CL incorrectly attempted to access
args[0].As<v8::Object>() even when the initial IDL validation
(args_converter.is_success() && !args[0]->IsObject()) failed. This
could lead to unpredictable behavior as args[0] might not be a valid
object. This reland fixes this by ensuring that
args[0].As<v8::Object>() is only accessed when
args_converter.is_success() is true.

Code changes: see the diff between Patchset 1 and Patchset 2

Original change's description:
> [shared storage] Implement sharedStorage.batchUpdate() for PA worklet
>
> Add sharedStorage.batchUpdate() function. Parse arguments into
> the 'methods' sequence and a 'with_lock' optional flag, and
> propagate the result to the browser process to invoke the
> `SharedStorageLockManager::SharedStorageBatchUpdate()` API.
>
> This allows developers to perform multiple Shared Storage operations atomically within a single lock, as part of the Web
> Lock integration proposal:
> - WICG/shared-storage#199
> - WICG/shared-storage#205
>
> Fuchsia-Binary-Size: Size increase is unavoidable.
> Bug: 373899210
> Change-Id: Ic6e9f794d78523ec9f6b87f37fb5e91f17635c58
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6072850
> Commit-Queue: Yao Xiao <yaoxia@chromium.org>
> Reviewed-by: Maks Orlovich <morlovich@chromium.org>
> Reviewed-by: Cammie Smith Barnes <cammie@chromium.org>
> Reviewed-by: Giovanni Ortuno Urquidi <ortuno@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1401673}

Bug: 373899210
Change-Id: I1782e6af1de95cc643053aa80c2a15f601da56a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6132126
Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Reviewed-by: Giovanni Ortuno Urquidi <ortuno@chromium.org>
Commit-Queue: Yao Xiao <yaoxia@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1403952}

shared-storage/web-locks-pa-worklet-batch-update.tentative.https.window.js

@@ -0,0 +1,102 @@
+// META: script=/resources/testdriver.js
+// META: script=/resources/testdriver-vendor.js
+// META: script=/common/utils.js
+// META: script=/fledge/tentative/resources/fledge-util.sub.js
+// META: script=/common/subset-tests.js
+// META: script=/shared-storage/resources/util.js
+// META: script=/fenced-frame/resources/utils.js
+// META: timeout=long
+
+"use strict;"
+
+subsetTest(promise_test, async test => {
+  let worklet = await sharedStorage.createWorklet('resources/simple-module.js');
+
+  const ancestor_key = token();
+  let url0 = generateURL("/shared-storage/resources/frame0.html",
+                         [ancestor_key]);
+  let url1 = generateURL("/shared-storage/resources/frame1.html",
+                         [ancestor_key]);
+
+  // Override the default resource path, as we are not running within the Fledge
+  // repository.
+  RESOURCE_PATH = '/fledge/tentative/resources/';
+
+  const pa_uuid = generateUuid(test);
+
+  let biddingLogicURL = createBiddingScriptURL(
+    {
+      generateBid:
+        `
+          sharedStorage.batchUpdate([
+              new SharedStorageAppendMethod('key', 'a'),
+              new SharedStorageAppendMethod('key', 'a')
+            ], {withLock: 'lock1'});
+
+          return {};
+        `
+    });
+
+  let decisionLogicURL = createDecisionScriptURL(pa_uuid);
+
+  // Invoke `selectURL()` to perform the following steps:
+  // 1. Acquires the lock.
+  // 2. Reads the current value at the given key.
+  // 3. Waits for 500ms.
+  // 4. Sets the shared storage value to the read value appended with the given letter.
+  // 5. Releases the lock.
+  //
+  // After 100ms, run a Protected Audience auction that starts a worklet that:
+  // - Acquires the same named lock.
+  // - Executes two `append` methods, each appending the same letter.
+  //
+  // Expected behavior: After both of them finish, the value at the given key
+  // should contain the letter repeated three times.
+  //
+  // This demonstrates that:
+  // 1. The `withLock` option is effective, preventing the `batchUpdate()`
+  //    method interfering with the "get and set" operation. If the lock were
+  //    not used, the final value would likely be a single letter.
+  // 2. `batchUpdate()` correctly executes all `append` methods within the
+  //    batch.
+  //
+  // Note: This test remains valid even if the `batchUpdate()` call happens
+  // outside the critical section protected by the lock within the worklet. The
+  // test effectively demonstrates mutual exclusion as long as there's a
+  // reasonable chance for `batchUpdate()` to occur while the worklet is still
+  // running.
+  let select_url_result = await worklet.selectURL(
+      "get-wait-set-within-lock",
+      [{url: url0}, {url: url1}],
+      {data: {'key': 'key',
+              'lock_name': 'lock1',
+              'append_letter': 'a'},
+      resolveToConfig: true});
+
+  // Busy wait for 100ms.
+  const startWaitTime = Date.now();
+  while (Date.now() - startWaitTime < 100) {}
+
+  // Run a Protected Audience auction which triggers `append()` with the same
+  // lock and the same letter.
+  await joinGroupAndRunBasicFledgeTestExpectingNoWinner(
+    test,
+    {
+      uuid: pa_uuid,
+      interestGroupOverrides: {
+        name: pa_uuid,
+        biddingLogicURL: biddingLogicURL,
+      },
+      auctionConfigOverrides: {
+        decisionLogicURL: decisionLogicURL
+      }
+    });
+
+  attachFencedFrame(select_url_result, 'opaque-ads');
+  const result = await nextValueFromServer(ancestor_key);
+  assert_equals(result, "frame1_loaded");
+
+  await verifyKeyValueForOrigin('key', 'aaa', location.origin);
+
+  await deleteKeyForOrigin('key', location.origin);
+}, 'Test for batchUpdate() with a batch lock in a Protected Audience Worklet context');