Implemented FormResubmissionTabHelper.

ios/chrome/browser/web/BUILD.gn

Index: ios/chrome/browser/web/BUILD.gn
diff --git a/ios/chrome/browser/web/BUILD.gn b/ios/chrome/browser/web/BUILD.gn
index b115bcc8b819f1e5f48004819fe35095e4c127b6..56c5d25b1b6e1d1c582f68f3151b3503c7effb9d 100644
--- a/ios/chrome/browser/web/BUILD.gn
+++ b/ios/chrome/browser/web/BUILD.gn
@@ -9,6 +9,8 @@ source_set("web") {
   sources = [
     "dom_altering_lock.h",
     "dom_altering_lock.mm",
+    "form_resubmission_tab_helper.h",
+    "form_resubmission_tab_helper.mm",
     "network_activity_indicator_tab_helper.h",
     "network_activity_indicator_tab_helper.mm",
   ]
@@ -16,6 +18,8 @@ source_set("web") {
     "//base",
     "//components/strings",
     "//ios/chrome/browser/ui",
+    "//ios/chrome/browser/ui/alert_coordinator:alert_coordinator",
+    "//ios/chrome/browser/ui/util:util",
     "//ios/web",
     "//ui/base",
   ]
@@ -25,12 +29,19 @@ source_set("unit_tests") {
   configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
+    "form_resubmission_tab_helper_unittest.mm",
     "network_activity_indicator_tab_helper_unittest.mm",
   ]
   deps = [
     ":web",
+    "//base:base",
+    "//base/test:test_support",
+    "//components/strings:components_strings_grit",
+    "//ios/chrome/browser/ui:ui",
+    "//ios/chrome/test:test_support",
     "//ios/web:test_support",
     "//testing/gtest",
+    "//ui/base:base",
   ]
 }