Use an MutationObserver to check when a password form disappears after XHR

third_party/WebKit/public/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/WebKit/public/public_features.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//third_party/WebKit/Source/core/core.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 590 matching lines @@
     "web/WebView.h",
     "web/WebViewClient.h",
     "web/WebWidget.h",
     "web/WebWidgetClient.h",
     "web/WebWindowFeatures.h",
     "web/WebWorkerContentSettingsClientProxy.h",
     "web/linux/WebFontRendering.h",
     "web/mac/WebScrollbarTheme.h",
     "web/mac/WebSubstringUtil.h",
     "web/mac/WebSubstringUtil.h",
+    "web/modules/password_manager/WebFormElementObserver.h",
+    "web/modules/password_manager/WebFormElementObserverCallback.h",
     "web/modules/serviceworker/WebServiceWorkerContextClient.h",
     "web/modules/serviceworker/WebServiceWorkerContextProxy.h",
     "web/win/WebFontRendering.h",
   ]
 
   if (is_android) {
     # Android uses some Linux sources, put those back.
     set_sources_assignment_filter([])
     sources += [
       "platform/linux/WebFontRenderStyle.h",
@@ skipping 190 matching lines @@
   sources = [
     "web/ConsoleMessageStructTraits.cpp",
     "web/ConsoleMessageStructTraits.h",
   ]
   deps = [
     ":blink_headers",
     ":mojo_bindings_shared__generator",
     "//mojo/public/cpp/bindings:struct_traits",
   ]
 }