diff --git a/IndexedDB/idb-explicit-commit-throw.any.js b/IndexedDB/idb-explicit-commit-throw.any.js
new file mode 100644
index 00000000000000..3b8d148d76c1e9
--- /dev/null
+++ b/IndexedDB/idb-explicit-commit-throw.any.js
@@ -0,0 +1,45 @@
+// META: script=support-promises.js
+
+/**
+ * This file contains a test that was separated out from the rest of the idb
+ * explict commit tests because it requires the flag 'allow_uncaught_exception',
+ * which prevents unintentionally thrown errors from failing tests.
+ *
+ * @author andreasbutler@google.com
+ */
+
+setup({allow_uncaught_exception:true});
+
+promise_test(async testCase => {
+  // Register an event listener that will prevent the intentionally thrown
+  // error from bubbling up to the window and failing the testharness. This
+  // is necessary because currently allow_uncaught_exception does not behave
+  // as expected for promise_test.
+  //
+  // Git issue: https://github.com/web-platform-tests/wpt/issues/14041
+  self.addEventListener('error', (event) => { event.preventDefault(); });
+
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  const putRequest = objectStore.put({isbn:'one', title:'title'});
+  txn.commit();
+  putRequest.onsuccess = () => {
+    throw new Error('This error thrown after an explicit commit should not ' +
+        'prevent the transaction from committing.');
+  }
+  await promiseForTransaction(testCase, txn);
+
+  // Ensure that despite the uncaught error after the put request, the explicit
+  // commit still causes the request to be committed.
+  const txn2 = db.transaction(['books'], 'readwrite');
+  const objectStore2 = txn2.objectStore('books');
+  const getRequest = objectStore2.get('one');
+  await promiseForTransaction(testCase, txn2);
+
+  assert_equals(getRequest.result.title, 'title');
+}, 'Any errors in callbacks that run after an explicit commit will not stop '
+   + 'the commit from being processed.');
diff --git a/IndexedDB/idb-explicit-commit.any.js b/IndexedDB/idb-explicit-commit.any.js
new file mode 100644
index 00000000000000..b2dec751b1a8f1
--- /dev/null
+++ b/IndexedDB/idb-explicit-commit.any.js
@@ -0,0 +1,181 @@
+// META: script=support-promises.js
+
+/**
+ * This file contains the webplatform tests for the explicit commit() method
+ * of the IndexedDB transaction API.
+ *
+ * @author andreasbutler@google.com
+ */
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  objectStore.put({isbn: 'one', title: 'title1'});
+  objectStore.put({isbn: 'two', title: 'title2'});
+  objectStore.put({isbn: 'three', title: 'title3'});
+  txn.commit();
+  await promiseForTransaction(testCase, txn);
+
+  const txn2 = db.transaction(['books'], 'readonly');
+  const objectStore2 = txn2.objectStore('books');
+  const getRequestitle1 = objectStore2.get('one');
+  const getRequestitle2 = objectStore2.get('two');
+  const getRequestitle3 = objectStore2.get('three');
+  txn2.commit();
+  await promiseForTransaction(testCase, txn2);
+  assert_array_equals(
+      [getRequestitle1.result.title,
+          getRequestitle2.result.title,
+          getRequestitle3.result.title],
+      ['title1', 'title2', 'title3'],
+      'All three retrieved titles should match those that were put.');
+  db.close();
+}, 'Explicitly committed data can be read back out.');
+
+
+promise_test(async testCase => {
+  let db = await createDatabase(testCase, () => {});
+  assert_equals(1, db.version, 'A database should be created as version 1');
+  db.close();
+
+  // Upgrade the versionDB database and explicitly commit its versionchange
+  // transaction.
+  db = await migrateDatabase(testCase, 2, async (db, txn) => {
+    txn.commit();
+  });
+  assert_equals(2, db.version,
+      'The database version should have been incremented regardless of '
+      + 'whether the versionchange transaction was explicitly or implicitly '
+      + 'committed.');
+  db.close();
+}, 'commit() on a version change transaction does not cause errors.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  txn.commit();
+  assert_throws('TransactionInactiveError',
+      () => { objectStore.put({isbn: 'one', title: 'title1'}); },
+      'After commit is called, the transaction should be inactive.');
+  db.close();
+}, 'A committed transaction becomes inactive immediately.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  const putRequest = objectStore.put({isbn: 'one', title: 'title1'});
+  putRequest.onsuccess = testCase.step_func(() => {
+    assert_throws('TransactionInactiveError',
+      () => { objectStore.put({isbn:'two', title:'title2'}); },
+      'The transaction should not be active in the callback of a request after '
+      + 'commit() is called.');
+  });
+  txn.commit();
+  await promiseForTransaction(testCase, txn);
+  db.close();
+}, 'A committed transaction is inactive in future request callbacks.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  txn.commit();
+
+  assert_throws('TransactionInactiveError',
+      () => { objectStore.put({isbn:'one', title:'title1'}); },
+      'After commit is called, the transaction should be inactive.');
+
+  const txn2 = db.transaction(['books'], 'readonly');
+  const objectStore2 = txn2.objectStore('books');
+  const getRequest = objectStore2.get('one');
+  await promiseForTransaction(testCase, txn2);
+  assert_equals(getRequest.result, undefined);
+
+  db.close();
+}, 'Puts issued after commit are not fulfilled.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  txn.abort();
+  assert_throws('InvalidStateError',
+      () => { txn.commit(); },
+      'The transaction should have been aborted.');
+  db.close();
+}, 'Calling commit on an aborted transaction throws.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  txn.commit();
+  assert_throws('InvalidStateError',
+      () => { txn.commit(); },
+      'The transaction should have already committed.');
+  db.close();
+}, 'Calling commit on a committed transaction throws.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  const putRequest = objectStore.put({isbn:'one', title:'title1'});
+  txn.commit();
+  assert_throws('InvalidStateError',
+      () => { txn.abort(); },
+      'The transaction should already have committed.');
+  const txn2 = db.transaction(['books'], 'readwrite');
+  const objectStore2 = txn2.objectStore('books');
+  const getRequest = objectStore2.get('one');
+  await promiseForTransaction(testCase, txn2);
+  assert_equals(
+      getRequest.result.title,
+      'title1',
+      'Explicitly committed data should be gettable.');
+  db.close();
+}, 'Calling abort on a committed transaction throws and does not prevent '
+   + 'persisting the data.');
+
+
+promise_test(async testCase => {
+  const db = await createDatabase(testCase, async db => {
+    await createBooksStore(testCase, db);
+  });
+  const txn = db.transaction(['books'], 'readwrite');
+  const objectStore = txn.objectStore('books');
+  const releaseTxnFunction = keepAlive(testCase, txn, 'books');
+
+  // Break up the scope of execution to force the transaction into an inactive
+  // state.
+  await timeoutPromise(0);
+
+  assert_throws('InvalidStateError',
+      () => { txn.commit(); },
+      'The transaction should be inactive so calling commit should throw.');
+  releaseTxnFunction();
+  db.close();
+}, 'Calling txn.commit() when txn is inactive should throw.');
diff --git a/IndexedDB/support-promises.js b/IndexedDB/support-promises.js
index 433af5092701d6..8195be341e1886 100644
--- a/IndexedDB/support-promises.js
+++ b/IndexedDB/support-promises.js
@@ -312,3 +312,32 @@ async function deleteAllDatabases(testCase) {
     await eventWatcher.wait_for('success');
   }
 }
+
+// Keeps the passed transaction alive indefinitely (by making requests
+// against the named store). Returns a function that asserts that the
+// transaction has not already completed and then ends the request loop so that
+// the transaction may autocommit and complete.
+function keepAlive(testCase, transaction, storeName) {
+  let completed = false;
+  transaction.addEventListener('complete', () => { completed = true; });
+
+  let keepSpinning = true;
+
+  function spin() {
+    if (!keepSpinning)
+      return;
+    transaction.objectStore(storeName).get(0).onsuccess = spin;
+  }
+  spin();
+
+  return testCase.step_func(() => {
+    assert_false(completed, 'Transaction completed while kept alive');
+    keepSpinning = false;
+  });
+}
+
+// Return a promise that resolves after a setTimeout finishes to break up the
+// scope of a function's execution.
+function timeoutPromise(ms) {
+  return new Promise(resolve => { setTimeout(resolve, ms); });
+}
diff --git a/IndexedDB/support.js b/IndexedDB/support.js
index 5edbdacbcc7d0c..d3b2bb7d1212dd 100644
--- a/IndexedDB/support.js
+++ b/IndexedDB/support.js
@@ -1,6 +1,3 @@
-var databaseName = "database";
-var databaseVersion = 1;
-
 /* Delete created databases
  *
  * Go through each finished test, see if it has an associated database. Close
@@ -170,18 +167,18 @@ function is_transaction_active(tx, store_name) {
   }
 }
 
-// Keep the passed transaction alive indefinitely (by making requests
-// against the named store). Returns a function to to let the
-// transaction finish, and asserts that the transaction is not yet
-// finished.
+// Keeps the passed transaction alive indefinitely (by making requests
+// against the named store). Returns a function that asserts that the
+// transaction has not already completed and then ends the request loop so that
+// the transaction may autocommit and complete.
 function keep_alive(tx, store_name) {
   let completed = false;
   tx.addEventListener('complete', () => { completed = true; });
 
-  let pin = true;
+  let keepSpinning = true;
 
   function spin() {
-    if (!pin)
+    if (!keepSpinning)
       return;
     tx.objectStore(store_name).get(0).onsuccess = spin;
   }
@@ -189,6 +186,6 @@ function keep_alive(tx, store_name) {
 
   return () => {
     assert_false(completed, 'Transaction completed while kept alive');
-    pin = false;
+    keepSpinning = false;
   };
 }