Track form changes on the web page.

Some web sites (like apple.com or llbean.com) build forms after the page
loading. This prevent using the server side type resolution.

Add a tracker to update the autofill forms regularly.

Bug: 798675
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ieaaf502a7bff38756d90bd96e94c058977dcab7b
Reviewed-on: https://chromium-review.googlesource.com/943321
Commit-Queue: Olivier Robin <olivierrobin@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544331}

build/util/java_action.gni

@@ -46,6 +46,7 @@ template("java_action") {
                              "deps",
                              "outputs",
                              "sources",
+                             "testonly",
                              "visibility",
                            ])
   }
@@ -95,6 +96,7 @@ template("java_action_foreach") {
                              "deps",
                              "outputs",
                              "sources",
+                             "testonly",
                              "visibility",
                            ])
   }

components/BUILD.gn

@@ -175,6 +175,7 @@ test("components_unittests") {
   if (is_ios) {
     deps += [
       "//components/autofill/ios/browser:unit_tests",
+      "//components/autofill/ios/fill:unit_tests",
       "//components/image_fetcher/ios:unit_tests",
       "//components/signin/ios/browser:unit_tests",
       "//components/translate/ios/browser:unit_tests",

components/autofill/ios/browser/autofill_agent.mm

@@ -726,7 +726,11 @@ void GetFormAndField(autofill::FormData* form,
 
   web::URLVerificationTrustLevel trustLevel;
   const GURL pageURL(webState->GetCurrentURL(&trustLevel));
+  [jsAutofillManager_ trackFormUpdates];
+  [self scanFormsInPage:webState pageURL:pageURL];
+}
 
+- (void)scanFormsInPage:(web::WebState*)webState pageURL:(const GURL&)pageURL {
   __weak AutofillAgent* weakSelf = self;
   id completionHandler = ^(BOOL success, const FormDataVector& forms) {
     AutofillAgent* strongSelf = weakSelf;
@@ -764,6 +768,17 @@ void GetFormAndField(autofill::FormData* form,
   // page is fully loaded.
   [self processPage:webState];
 
+  web::URLVerificationTrustLevel trustLevel;
+  const GURL pageURL(webState->GetCurrentURL(&trustLevel));
+
+  // If the event is a form_changed, then the event concerns the whole page and
+  // not a particular form. The whole page need to be reparsed to find the new
+  // forms.
+  if (params.type.compare("form_changed") == 0) {
+    [self scanFormsInPage:webState pageURL:pageURL];
+    return;
+  }
+
   // Blur not handled; we don't reset the suggestion state because if the
   // keyboard is about to be dismissed there's no point. If not it means the
   // next focus event will update the suggestion state within milliseconds, so
@@ -785,9 +800,6 @@ void GetFormAndField(autofill::FormData* form,
     }
   };
 
-  web::URLVerificationTrustLevel trustLevel;
-  const GURL pageURL(webState->GetCurrentURL(&trustLevel));
-
   // Re-extract the active form and field only. There is no minimum field
   // requirement because key/value suggestions are offered even on short forms.
   [self fetchFormsFiltered:YES

components/autofill/ios/browser/js_autofill_manager.h

@@ -52,6 +52,9 @@
 // Adds a delay between filling the form fields.
 - (void)addJSDelay;
 
+// Installs a tracker to check the form updates in the page every 500ms.
+- (void)trackFormUpdates;
+
 // Designated initializer. |receiver| should not be nil.
 - (instancetype)initWithReceiver:(CRWJSInjectionReceiver*)receiver
     NS_DESIGNATED_INITIALIZER;

components/autofill/ios/browser/js_autofill_manager.mm

@@ -74,6 +74,11 @@
              }];
 }
 
+- (void)trackFormUpdates {
+  [_receiver executeJavaScript:@"__gCrWeb.form.trackFormUpdates(500)"
+             completionHandler:nil];
+}
+
 - (void)fillForm:(NSString*)dataString
     forceFillFieldName:(NSString*)forceFillFieldName
      completionHandler:(ProceduralBlock)completionHandler {

components/autofill/ios/fill/BUILD.gn

+# Copyright 2018 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("//ios/web/js_compile.gni")
+import("//testing/test.gni")
+
+source_set("unit_tests") {
+  testonly = true
+  configs += [ "//build/config/compiler:enable_arc" ]
+  sources = [
+    "form_unittest.mm",
+  ]
+  deps = [
+    ":form_js",
+    "//base",
+    "//ios/web/public/test",
+    "//ios/web/public/test/fakes",
+    "//ios/web/web_state/js",
+    "//testing/gtest",
+  ]
+}
+
+js_compile_checked("form_js") {
+  visibility = [ ":unit_tests" ]
+  testonly = true
+  sources = [
+    "resources/form.js",
+  ]
+}

components/autofill/ios/fill/DEPS

+specific_include_rules = {
+  "form_unittest\.mm": [
+    "+ios/web/web_state/js/page_script_util.h",
+  ],
+}

ios/web/web_state/js/form_inttest.mm → components/autofill/ios/fill/form_unittest.mm

@@ -2,25 +2,41 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#import "ios/web/public/browser_state.h"
+#import "ios/web/public/test/fakes/test_web_client.h"
 #include "ios/web/public/test/fakes/test_web_state_observer.h"
+#import "ios/web/public/test/web_js_test.h"
 #import "ios/web/public/test/web_test_with_web_state.h"
+#import "ios/web/web_state/js/page_script_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-namespace web {
+class FormTestClient : public web::TestWebClient {
+ public:
+  NSString* GetDocumentStartScriptForAllFrames(
+      web::BrowserState* browser_state) const override {
+    return web::GetPageScript(@"form");
+  }
+};
 
-using FormJsTest = WebTestWithWebState;
+// Text fixture to test password controller.
+class FormJsTest : public web::WebJsTest<web::WebTestWithWebState> {
+ public:
+  FormJsTest()
+      : web::WebJsTest<web::WebTestWithWebState>(
+            std::make_unique<FormTestClient>()) {}
+};
 
 // Tests that keyup event correctly delivered to WebStateObserver.
 TEST_F(FormJsTest, KeyUpEvent) {
-  TestWebStateObserver observer(web_state());
+  web::TestWebStateObserver observer(web_state());
   LoadHtml(@"<p></p>");
   ASSERT_FALSE(observer.form_activity_info());
   ExecuteJavaScript(@"document.dispatchEvent(new KeyboardEvent('keyup'));");
-  TestFormActivityInfo* info = observer.form_activity_info();
+  web::TestFormActivityInfo* info = observer.form_activity_info();
   ASSERT_TRUE(info);
   EXPECT_EQ("keyup", info->form_activity.type);
   EXPECT_FALSE(info->form_activity.input_missing);
@@ -28,7 +44,7 @@ TEST_F(FormJsTest, KeyUpEvent) {
 
 // Tests that focus event correctly delivered to WebStateObserver.
 TEST_F(FormJsTest, FocusMainFrame) {
-  TestWebStateObserver observer(web_state());
+  web::TestWebStateObserver observer(web_state());
   LoadHtml(
       @"<form>"
        "<input type='text' name='username' id='id1'>"
@@ -36,7 +52,7 @@ TEST_F(FormJsTest, FocusMainFrame) {
        "</form>");
   ASSERT_FALSE(observer.form_activity_info());
   ExecuteJavaScript(@"document.getElementById('id1').focus();");
-  TestFormActivityInfo* info = observer.form_activity_info();
+  web::TestFormActivityInfo* info = observer.form_activity_info();
   ASSERT_TRUE(info);
   EXPECT_EQ("focus", info->form_activity.type);
   EXPECT_FALSE(info->form_activity.input_missing);
@@ -44,7 +60,7 @@ TEST_F(FormJsTest, FocusMainFrame) {
 
 // Tests that submit event correctly delivered to WebStateObserver.
 TEST_F(FormJsTest, FormSubmitMainFrame) {
-  TestWebStateObserver observer(web_state());
+  web::TestWebStateObserver observer(web_state());
   LoadHtml(
       @"<form id='form1'>"
        "<input type='password'>"
@@ -52,7 +68,7 @@ TEST_F(FormJsTest, FormSubmitMainFrame) {
        "</form>");
   ASSERT_FALSE(observer.submit_document_info());
   ExecuteJavaScript(@"document.getElementById('submit_input').click();");
-  TestSubmitDocumentInfo* info = observer.submit_document_info();
+  web::TestSubmitDocumentInfo* info = observer.submit_document_info();
   ASSERT_TRUE(info);
   EXPECT_EQ("form1", info->form_name);
 }
@@ -60,7 +76,7 @@ TEST_F(FormJsTest, FormSubmitMainFrame) {
 // Tests that focus event from same-origin iframe correctly delivered to
 // WebStateObserver.
 TEST_F(FormJsTest, FocusSameOriginIFrame) {
-  TestWebStateObserver observer(web_state());
+  web::TestWebStateObserver observer(web_state());
   LoadHtml(@"<iframe id='frame1'></iframe>");
   ExecuteJavaScript(
       @"document.getElementById('frame1').contentDocument.body.innerHTML = "
@@ -72,7 +88,7 @@ TEST_F(FormJsTest, FocusSameOriginIFrame) {
   ExecuteJavaScript(
       @"document.getElementById('frame1').contentDocument.getElementById('id1')"
       @".focus()");
-  TestFormActivityInfo* info = observer.form_activity_info();
+  web::TestFormActivityInfo* info = observer.form_activity_info();
   ASSERT_TRUE(info);
   EXPECT_EQ("focus", info->form_activity.type);
   EXPECT_FALSE(info->form_activity.input_missing);
@@ -81,7 +97,7 @@ TEST_F(FormJsTest, FocusSameOriginIFrame) {
 // Tests that submit event from same-origin iframe correctly delivered to
 // WebStateObserver.
 TEST_F(FormJsTest, FormSameOriginIFrame) {
-  TestWebStateObserver observer(web_state());
+  web::TestWebStateObserver observer(web_state());
   LoadHtml(@"<iframe id='frame1'></iframe>");
   ExecuteJavaScript(
       @"document.getElementById('frame1').contentDocument.body.innerHTML = "
@@ -92,9 +108,45 @@ TEST_F(FormJsTest, FormSameOriginIFrame) {
   ExecuteJavaScript(
       @"document.getElementById('frame1').contentDocument.getElementById('"
       @"submit_input').click();");
-  TestSubmitDocumentInfo* info = observer.submit_document_info();
+  web::TestSubmitDocumentInfo* info = observer.submit_document_info();
   ASSERT_TRUE(info);
   EXPECT_EQ("form1", info->form_name);
 }
 
-}  // namespace web
+// Tests that new form triggers form changed event.
+TEST_F(FormJsTest, FocusAddForm) {
+  web::TestWebStateObserver observer(web_state());
+  LoadHtml(@"<form/>");
+
+  ExecuteJavaScript(
+      @"__gCrWeb.form.trackFormUpdates(10);"
+      @"var form = document.createElement('form');"
+      @"document.body.appendChild(form);");
+  web::TestWebStateObserver* block_observer = &observer;
+  __block web::TestFormActivityInfo* info = nil;
+  WaitForCondition(^{
+    info = block_observer->form_activity_info();
+    return info != nil;
+  });
+  EXPECT_EQ("form_changed", info->form_activity.type);
+  EXPECT_FALSE(info->form_activity.input_missing);
+}
+
+// Tests that new input triggers form changed event.
+TEST_F(FormJsTest, FocusAddInput) {
+  web::TestWebStateObserver observer(web_state());
+  LoadHtml(@"<form id='formId'/>");
+
+  ExecuteJavaScript(
+      @"__gCrWeb.form.trackFormUpdates(10);"
+      @"var input = document.createElement('input');"
+      @"document.getElementById('formId').appendChild(input);");
+  web::TestWebStateObserver* block_observer = &observer;
+  __block web::TestFormActivityInfo* info = nil;
+  WaitForCondition(^{
+    info = block_observer->form_activity_info();
+    return info != nil;
+  });
+  EXPECT_EQ("form_changed", info->form_activity.type);
+  EXPECT_FALSE(info->form_activity.input_missing);
+}

ios/web/web_state/js/resources/form.js → components/autofill/ios/fill/resources/form.js

@@ -11,8 +11,6 @@
 
 goog.provide('__crWeb.form');
 
-goog.require('__crWeb.message');
-
 /**
  * Namespace for this file. It depends on |__gCrWeb| having already been
  * injected. String 'form' is used in |__gCrWeb['form']| as it needs to be
@@ -50,6 +48,17 @@ __gCrWeb.form.kNamelessFormIDPrefix = 'gChrome~form~';
  */
 __gCrWeb.form.kNamelessFieldIDPrefix = 'gChrome~field~';
 
+/**
+ * The interval watching for form changes.
+ */
+__gCrWeb.form.formWatcherInterval = null;
+
+/**
+ * The value of the form signature last time formWatcherInterval was
+ * triggerred.
+ */
+__gCrWeb.form.lastFormSignature = {};
+
 /**
  * Based on Element::isFormControlElement() (WebKit)
  * @param {Element} element A DOM element.
@@ -282,6 +291,48 @@ var getFullyQualifiedUrl_ = function(originalURL) {
   return anchor.href;
 };
 
+  /**
+   * Returns a simple signature of the form content of the page. Must be fast
+   * as it is called regularly.
+   */
+  var getFormSignature_ = function() {
+    return {
+      forms: document.forms.length,
+      input: document.getElementsByTagName('input').length
+    };
+  };
+
+  /**
+   * Install a watcher to check the form changes. Delay is the interval between
+   * checks in milliseconds.
+   */
+  __gCrWeb.form['trackFormUpdates'] = function(delay) {
+    if (__gCrWeb.form.formWatcherInterval) {
+      clearInterval(__gCrWeb.form.formWatcherInterval);
+      __gCrWeb.form.formWatcherInterval = null;
+    }
+    if (delay) {
+      __gCrWeb.form.lastFormSignature = getFormSignature_();
+      __gCrWeb.form.formWatcherInterval = setInterval(function() {
+        var signature = getFormSignature_();
+        var old_signature = __gCrWeb.form.lastFormSignature;
+        if (signature.forms != old_signature.forms ||
+            signature.input != old_signature.input) {
+          var msg = {
+            'command': 'form.activity',
+            'formName': '',
+            'fieldName': '',
+            'fieldType': '',
+            'type': 'form_changed',
+            'value': ''
+          };
+          __gCrWeb.form.lastFormSignature = signature;
+          __gCrWeb.message.invokeOnHost(msg);
+        }
+      }, delay);
+    }
+  };
+
 /** Flush the message queue. */
 if (__gCrWeb.message) {
   __gCrWeb.message.invokeQueues();

ios/chrome/browser/passwords/BUILD.gn

@@ -192,7 +192,7 @@ js_compile_checked("injected_js") {
     "resources/password_controller.js",
   ]
   js_modules = [
-    "//ios/web/web_state/js/resources/form.js",
+    "//components/autofill/ios/fill/resources/form.js",
     "//components/autofill/ios/fill/resources/fill.js",
   ]
 }

ios/chrome/browser/passwords/password_controller_js_unittest.mm

@@ -22,8 +22,10 @@ class PasswordControllerJsTest
     : public web::WebJsTest<web::WebTestWithWebState> {
  public:
   PasswordControllerJsTest()
-      : web::WebJsTest<web::WebTestWithWebState>(
-            @[ @"chrome_bundle", @"password_controller" ]) {}
+      : web::WebJsTest<web::WebTestWithWebState>(@[
+          @"chrome_bundle_all_frames", @"chrome_bundle_main_frame",
+          @"password_controller"
+        ]) {}
 };
 
 // IDs used in the Username and Password <input> elements.

ios/chrome/browser/web/BUILD.gn

@@ -108,12 +108,20 @@ source_set("unit_tests") {
   ]
 }
 
-js_compile_bundle("chrome_bundle") {
-  closure_entry_point = "__crWeb.chromeBundle"
+js_compile_bundle("chrome_bundle_all_frames") {
+  closure_entry_point = "__crWeb.chromeBundleAllFrames"
+  sources = [
+    "//components/autofill/ios/fill/resources/form.js",
+    "resources/chrome_bundle_all_frames.js",
+  ]
+}
+
+js_compile_bundle("chrome_bundle_main_frame") {
+  closure_entry_point = "__crWeb.chromeBundleMainFrame"
   sources = [
     "//components/autofill/ios/browser/resources/autofill_controller.js",
     "//components/autofill/ios/fill/resources/fill.js",
-    "resources/chrome_bundle.js",
+    "resources/chrome_bundle_main_frame.js",
     "resources/print.js",
   ]
 
@@ -155,7 +163,8 @@ source_set("web_internal") {
     "web_state_printer.h",
   ]
   deps = [
-    ":chrome_bundle",
+    ":chrome_bundle_all_frames",
+    ":chrome_bundle_main_frame",
     "//base",
     "//components/content_settings/core/browser",
     "//components/dom_distiller/core",

ios/chrome/browser/web/chrome_web_client.h

@@ -38,6 +38,8 @@ class ChromeWebClient : public web::WebClient {
       std::vector<std::string>* additional_schemes) override;
   void PostBrowserURLRewriterCreation(
       web::BrowserURLRewriter* rewriter) override;
+  NSString* GetDocumentStartScriptForAllFrames(
+      web::BrowserState* browser_state) const override;
   NSString* GetDocumentStartScriptForMainFrame(
       web::BrowserState* browser_state) const override;
   void AllowCertificateError(

ios/chrome/browser/web/chrome_web_client.mm

@@ -173,10 +173,15 @@ void ChromeWebClient::PostBrowserURLRewriterCreation(
   rewriter->AddURLRewriter(&WillHandleWebBrowserAboutURL);
 }
 
+NSString* ChromeWebClient::GetDocumentStartScriptForAllFrames(
+    web::BrowserState* browser_state) const {
+  return GetPageScript(@"chrome_bundle_all_frames");
+}
+
 NSString* ChromeWebClient::GetDocumentStartScriptForMainFrame(
     web::BrowserState* browser_state) const {
   NSMutableArray* scripts = [NSMutableArray array];
-  [scripts addObject:GetPageScript(@"chrome_bundle")];
+  [scripts addObject:GetPageScript(@"chrome_bundle_main_frame")];
 
   if (base::FeatureList::IsEnabled(features::kCredentialManager)) {
     [scripts addObject:GetPageScript(@"credential_manager")];

ios/chrome/browser/web/resources/chrome_bundle_all_frames.js

+// Copyright 2017 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.
+
+// The set of scripts to be injected into the web view as early as possible.
+goog.provide('__crWeb.chromeBundleAllFrames');
+
+goog.require('__crWeb.form');

ios/chrome/browser/web/resources/chrome_bundle.js → ios/chrome/browser/web/resources/chrome_bundle_main_frame.js

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 // The set of scripts to be injected into the web view as early as possible.
-goog.provide('__crWeb.chromeBundle');
+goog.provide('__crWeb.chromeBundleMainFrame');
 
 goog.require('__crWeb.autofill');
 goog.require('__crWeb.fill');

ios/web/BUILD.gn

@@ -570,7 +570,6 @@ test("ios_web_inttests") {
     "url_loader_inttest.mm",
     "web_state/favicon_callbacks_inttest.mm",
     "web_state/http_auth_inttest.mm",
-    "web_state/js/form_inttest.mm",
     "web_state/navigation_and_load_callbacks_inttest.mm",
     "webui/web_ui_mojo_inttest.mm",
   ]
@@ -614,7 +613,6 @@ js_compile_bundle("all_frames_web_bundle") {
     "web_state/js/resources/all_frames_web_bundle.js",
     "web_state/js/resources/base.js",
     "web_state/js/resources/common.js",
-    "web_state/js/resources/form.js",
     "web_state/js/resources/message.js",
   ]
 }

ios/web/js_compile.gni

@@ -44,6 +44,7 @@ template("js_compile_bundle") {
 
   java_action(compile_js_target_name) {
     visibility = [ ":$_target_name" ]
+    forward_variables_from(invoker, [ "testonly" ])
     script = closure_compiler_path
     sources = invoker.sources
     outputs = [
@@ -68,6 +69,7 @@ template("js_compile_bundle") {
                              "data_deps",
                              "deps",
                              "public_deps",
+                             "testonly",
                              "visibility",
                            ])
 
@@ -114,6 +116,7 @@ template("js_compile_checked") {
 
     java_action_foreach(compile_js_target_name) {
       visibility = [ ":$_target_name" ]
+      forward_variables_from(invoker, [ "testonly" ])
       script = closure_compiler_path
       sources = invoker.sources
       _js_modules = [
@@ -178,6 +181,7 @@ template("js_compile_checked") {
                                "data_deps",
                                "deps",
                                "public_deps",
+                               "testonly",
                                "visibility",
                              ])
 
@@ -197,6 +201,7 @@ template("js_compile_checked") {
                                "data_deps",
                                "deps",
                                "public_deps",
+                               "testonly",
                                "visibility",
                              ])
 
@@ -233,6 +238,7 @@ template("js_compile_unchecked") {
 
     java_action_foreach(compile_js_target_name) {
       visibility = [ ":$_target_name" ]
+      forward_variables_from(invoker, [ "testonly" ])
       script = closure_compiler_path
       sources = invoker.sources
       outputs = [
@@ -255,6 +261,7 @@ template("js_compile_unchecked") {
                                "data_deps",
                                "deps",
                                "public_deps",
+                               "testonly",
                                "visibility",
                              ])
 
@@ -274,6 +281,7 @@ template("js_compile_unchecked") {
                                "data_deps",
                                "deps",
                                "public_deps",
+                               "testonly",
                                "visibility",
                              ])
 

ios/web/public/test/BUILD.gn

@@ -6,6 +6,10 @@ source_set("test") {
   configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
 
+  public_deps = [
+    "//ios/web/public/test/fakes",
+  ]
+
   deps = [
     "//base",
     "//base/test:test_support",
@@ -13,7 +17,6 @@ source_set("test") {
     "//ios/web:web",
     "//ios/web/interstitials",
     "//ios/web/navigation:core",
-    "//ios/web/public/test/fakes",
     "//ios/web/public/test/http_server",
     "//ios/web/test:test_support",
     "//testing/gtest",

ios/web/public/test/fakes/BUILD.gn

@@ -8,7 +8,6 @@ source_set("fakes") {
 
   deps = [
     "//base",
-    "//ios/web/public",
     "//ios/web/public/download",
     "//ios/web/test:test_constants",
     "//ios/web/web_state:navigation_context",
@@ -20,6 +19,10 @@ source_set("fakes") {
     "//ui/base",
   ]
 
+  public_deps = [
+    "//ios/web/public",
+  ]
+
   sources = [
     "crw_test_js_injection_receiver.h",
     "crw_test_js_injection_receiver.mm",

ios/web/public/test/web_test_with_web_state.mm

@@ -171,7 +171,7 @@ void WebTestWithWebState::WaitForBackgroundTasks() {
 
 void WebTestWithWebState::WaitForCondition(ConditionBlock condition) {
   base::test::ios::WaitUntilCondition(condition, true,
-                                      base::TimeDelta::FromSeconds(10));
+                                      base::TimeDelta::FromSeconds(1000));
 }
 
 id WebTestWithWebState::ExecuteJavaScript(NSString* script) {

ios/web/public/web_client.h

@@ -120,6 +120,16 @@ class WebClient {
 
   // Gives the embedder a chance to provide the JavaScript to be injected into
   // the web view as early as possible. Result must not be nil.
+  // The script returned will be injected in all frames (main and subframes).
+  //
+  // TODO(crbug.com/703964): Change the return value to NSArray<NSString*> to
+  // improve performance.
+  virtual NSString* GetDocumentStartScriptForAllFrames(
+      BrowserState* browser_state) const;
+
+  // Gives the embedder a chance to provide the JavaScript to be injected into
+  // the web view as early as possible. Result must not be nil.
+  // The script returned will only be injected in the main frame.
   //
   // TODO(crbug.com/703964): Change the return value to NSArray<NSString*> to
   // improve performance.

ios/web/public/web_state/web_state_observer.h

@@ -138,6 +138,7 @@ class WebStateObserver {
   // Called on form submission in the main frame or in a same-origin iframe.
   // |user_initiated| is true if the user interacted with the page.
   // |is_main_frame| is true if the submitted form is in the main frame.
+  // TODO(crbug.com/823285): move this handler to components/autofill.
   virtual void DocumentSubmitted(WebState* web_state,
                                  const std::string& form_name,
                                  bool user_initiated,
@@ -146,6 +147,7 @@ class WebStateObserver {
   // Called when the user is typing on a form field in the main frame or in a
   // same-origin iframe. |params.input_missing| is indicating if there is any
   // error when parsing the form field information.
+  // TODO(crbug.com/823285): move this handler to components/autofill.
   virtual void FormActivityRegistered(WebState* web_state,
                                       const FormActivityParams& params) {}
 

ios/web/web_client.mm

@@ -70,6 +70,11 @@ base::RefCountedMemory* WebClient::GetDataResourceBytes(int resource_id) const {
   return nullptr;
 }
 
+NSString* WebClient::GetDocumentStartScriptForAllFrames(
+    BrowserState* browser_state) const {
+  return @"";
+}
+
 NSString* WebClient::GetDocumentStartScriptForMainFrame(
     BrowserState* browser_state) const {
   return @"";

ios/web/web_state/js/page_script_util.mm

@@ -93,8 +93,14 @@ NSString* GetDocumentStartScriptForMainFrame(BrowserState* browser_state) {
 }
 
 NSString* GetDocumentStartScriptForAllFrames(BrowserState* browser_state) {
-  return MakeScriptInjectableOnce(@"start_all_frames",
-                                  GetPageScript(@"all_frames_web_bundle"));
+  DCHECK(GetWebClient());
+  NSString* embedder_page_script =
+      GetWebClient()->GetDocumentStartScriptForAllFrames(browser_state);
+  DCHECK(embedder_page_script);
+  NSString* web_bundle = GetPageScript(@"all_frames_web_bundle");
+  NSString* script =
+      [NSString stringWithFormat:@"%@; %@", web_bundle, embedder_page_script];
+  return MakeScriptInjectableOnce(@"start_all_frames", script);
 }
 
 NSString* GetDocumentEndScriptForAllFrames(BrowserState* browser_state) {

ios/web/web_state/js/resources/all_frames_web_bundle.js

@@ -5,4 +5,7 @@
 // Set of scripts required by web layer backed up by WKWebView.
 goog.provide('__crWeb.allFramesWebBundle');
 
-goog.require('__crWeb.form');
+goog.require('__crWeb.base');
+goog.require('__crWeb.common');
+goog.require('__crWeb.message');
+

ios/web/web_state/ui/crw_web_controller.mm

@@ -831,9 +831,11 @@ typedef void (^ViewportStateCompletion)(const web::PageViewportState*);
 - (BOOL)handleDocumentFaviconsMessage:(base::DictionaryValue*)message
                               context:(NSDictionary*)context;
 // Handles 'document.submit' message.
+// TODO(crbug.com/823285): move this handler to components/autofill.
 - (BOOL)handleDocumentSubmitMessage:(base::DictionaryValue*)message
                             context:(NSDictionary*)context;
 // Handles 'form.activity' message.
+// TODO(crbug.com/823285): move this handler to components/autofill.
 - (BOOL)handleFormActivityMessage:(base::DictionaryValue*)message
                           context:(NSDictionary*)context;
 // Handles 'window.error' message.

ios/web_view/BUILD.gn

@@ -312,6 +312,7 @@ js_compile_bundle("web_view_bundle") {
   sources = [
     "//components/autofill/ios/browser/resources/autofill_controller.js",
     "//components/autofill/ios/fill/resources/fill.js",
+    "//components/autofill/ios/fill/resources/form.js",
     "resources/web_view_bundle.js",
   ]
 }

ios/web_view/resources/web_view_bundle.js

@@ -7,3 +7,4 @@ goog.provide('__crWeb.webViewBundle');
 
 goog.require('__crWeb.autofill');
 goog.require('__crWeb.fill');
+goog.require('__crWeb.form');