[EditContext] Remove textInputController reference from WPT

Remove a reference to textInputController from EditContext WPT.
It looks like it was the result of a bad copy/paste; it would prevent
the test from passing outside of content_shell, and isn't relevant
to what the test is actually checking.

Bug: 999184
Change-Id: Iad2f6d7c6eedcc51721758c165babf881571d907
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4977879
Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Dan Clark <daniec@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1215286}
diff --git a/editing/edit-context/edit-context-input.tentative.html b/editing/edit-context/edit-context-input.tentative.html
index 0f05606..f65dfbc 100644
--- a/editing/edit-context/edit-context-input.tentative.html
+++ b/editing/edit-context/edit-context-input.tentative.html
@@ -31,8 +31,6 @@
       document.body.appendChild(test);
       test.editContext = editContext;
       test.focus();
-      textInputController.setComposition("foo");
-      assert_equals(test.innerHTML, "");
       await test_driver.send_keys(test, 'a');
       assert_equals(test.innerHTML, "");
       test.remove();