Remove kRestoreOnLoad flag in form_controller.cc

The behavior with kRestoreOnLoad==true caused one regression,
crbug.com/1035662, and it was fixed. We think the new behavior has no
major issues, and we don't need to keep the old behavior.
This CL has no behavior changes.

Bug: 1008708
Change-Id: I449a5d90489f9729dfd85aa9d0d229461967bc45
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2038410Reviewed-by: Mason Freed <masonfreed@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738715}

third_party/blink/renderer/core/html/forms/form_controller.cc

@@ -42,10 +42,6 @@ namespace blink {
 
 namespace {
 
-// TODO(crbug.com/1008708): Remove this flag when we're sure the new behavior
-// is better than the previous one.
-constexpr bool kRestoreOnLoad = true;
-
 inline HTMLFormElement* OwnerFormForState(const ListedElement& control) {
   // Assume controls with form attribute have no owners because we restore
   // state during parsing and form owners of such controls might be
@@ -568,7 +564,7 @@ void FormController::WillDeleteForm(HTMLFormElement* form) {
 }
 
 void FormController::RestoreControlStateFor(ListedElement& control) {
-  if (kRestoreOnLoad && !document_->HasFinishedParsing())
+  if (!document_->HasFinishedParsing())
     return;
   if (OwnerFormForState(control))
     return;
@@ -576,7 +572,7 @@ void FormController::RestoreControlStateFor(ListedElement& control) {
 }
 
 void FormController::RestoreControlStateIn(HTMLFormElement& form) {
-  if (kRestoreOnLoad && !document_->HasFinishedParsing())
+  if (!document_->HasFinishedParsing())
     return;
   EventQueueScope scope;
   const ListedElement::List& elements = form.ListedElements();
@@ -620,8 +616,6 @@ void FormController::RestoreControlStateOnUpgrade(ListedElement& control) {
 }
 
 void FormController::ScheduleRestore() {
-  if (!kRestoreOnLoad)
-    return;
   document_->GetTaskRunner(TaskType::kInternalLoading)
       ->PostTask(FROM_HERE,
                  WTF::Bind(&FormController::RestoreAllControlsInDocumentOrder,
@@ -629,8 +623,6 @@ void FormController::ScheduleRestore() {
 }
 
 void FormController::RestoreImmediately() {
-  if (!kRestoreOnLoad)
-    return;
   if (did_restore_all_ || !HasControlStates())
     return;
   RestoreAllControlsInDocumentOrder();