Have CookieStore reject cookies with no name and no value.

The CookieStore spec recently changed to disallow setting cookies
using this API:

https://github.com/WICG/cookie-store/pull/150

This CL updates the implementation of CookieStore in Blink to
perform this additional check and updates the web platform
tests to reflect the new changes to the spec.

Bug: 1108964
Change-Id: I1bc60332551308498509c0e8bbc6823bd8375ab8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2316622Reviewed-by: Ayu Ishii <ayui@chromium.org>
Commit-Queue: Dylan Cutler <dylancutler@google.com>
Cr-Commit-Position: refs/heads/master@{#791963}

third_party/blink/renderer/modules/cookie_store/cookie_store.cc

@@ -77,6 +77,11 @@ base::Optional<CanonicalCookie> ToCanonicalCookie(
         "Cookie value cannot contain '=' if the name is empty");
     return base::nullopt;
   }
+  if (name.IsEmpty() && value.IsEmpty()) {
+    exception_state.ThrowTypeError(
+        "Cookie name and value both cannot be empty");
+    return base::nullopt;
+  }
 
   base::Time expires = options->hasExpiresNonNull()
                            ? base::Time::FromJavaTime(options->expiresNonNull())
@@ -307,7 +312,7 @@ ScriptPromise CookieStore::Delete(ScriptState* script_state,
 
   CookieInit* set_options = CookieInit::Create();
   set_options->setName(name);
-  set_options->setValue(g_empty_string);
+  set_options->setValue("deleted");
   set_options->setExpires(0);
   return DoWrite(script_state, set_options, exception_state);
 }
@@ -317,7 +322,7 @@ ScriptPromise CookieStore::Delete(ScriptState* script_state,
                                   ExceptionState& exception_state) {
   CookieInit* set_options = CookieInit::Create();
   set_options->setName(options->name());
-  set_options->setValue(g_empty_string);
+  set_options->setValue("deleted");
   set_options->setExpires(0);
   set_options->setDomain(options->domain());
   set_options->setPath(options->path());

third_party/blink/web_tests/external/wpt/cookie-store/change_eventhandler_for_no_name_and_no_value.tentative.https.window.js

@@ -14,15 +14,25 @@ cookie_test(async t => {
     eventPromise, {changed: [{name: '', value: 'first-value'}]},
     'Observed no-name change');
 
-  eventPromise = observeNextCookieChangeEvent();
-  await cookieStore.set('', '');
-  const actual2 =
-      (await cookieStore.getAll('')).map(({ value }) => value).join(';');
-  const expected2 = '';
-  assert_equals(actual2, expected2);
-  await verifyCookieChangeEvent(
-    eventPromise, {changed: [{name: '', value: ''}]},
-    'Observed no-name change');
+  await promise_rejects_js(
+    t,
+    TypeError,
+    cookieStore.set('', ''),
+    'Expected promise rejection when setting a cookie with' +
+      ' no name and no value');
+
+  await promise_rejects_js(
+    t,
+    TypeError,
+    cookieStore.set({name: '', value: ''}),
+    'Expected promise rejection when setting a cookie with' +
+      ' no name and no value');
+
+  const cookies = await cookieStore.getAll('');
+  assert_equals(cookies.length, 1);
+  assert_equals(cookies[0].name, '');
+  assert_equals(cookies[0].value, 'first-value',
+      'Cookie with no name should still have previous value.');
 
   eventPromise = observeNextCookieChangeEvent();
   await cookieStore.delete('');

third_party/blink/web_tests/external/wpt/cookie-store/cookieStore_delete_arguments.tentative.https.any.js

@@ -147,3 +147,25 @@ promise_test(async testCase => {
   const cookie = await cookieStore.get('cookie-name');
   assert_equals(cookie, null);
 }, 'cookieStore.delete with get result');
+
+promise_test(async testCase => {
+  await cookieStore.set('', 'cookie-value');
+  testCase.add_cleanup(async () => {
+    await cookieStore.delete('');
+  });
+
+  await cookieStore.delete('');
+  const cookie = await cookieStore.get('');
+  assert_equals(cookie, null);
+}, 'cookieStore.delete with positional empty name');
+
+promise_test(async testCase => {
+  await cookieStore.set('', 'cookie-value');
+  testCase.add_cleanup(async () => {
+    await cookieStore.delete('');
+  });
+
+  await cookieStore.delete({ name: '' });
+  const cookie = await cookieStore.get('');
+  assert_equals(cookie, null);
+}, 'cookieStore.delete with empty name in options');