Remove LayoutFileUploadControl::UpdateFromElement()

* FileInputType::SetValue()
 |input.value =""| triggered style recalc because style recalc triggered
 UpdateFromElement(). However, we don't need style recalc in this case
 and we need to do just paint invalidation.

* UpdateFromElement() just does paint invalidation. The function is
 called from
 - HTMLFormControlElement::AttachLayoutTree()
 - HTMLFormControlElement::DidRecalcStyle()
  For both of them, paint invalidation by UpdateFromElement() is
  redundant. So we can remove UpdateFromElement().

This CL has no behavior changes.

Bug: 1040828
Change-Id: I3e180de69cef7eef20d1944283938deec8de9685
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2006436Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732784}

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

@@ -24,7 +24,6 @@
 
 #include "third_party/blink/public/platform/file_path_conversion.h"
 #include "third_party/blink/public/strings/grit/blink_strings.h"
-#include "third_party/blink/renderer/core/css/style_change_reason.h"
 #include "third_party/blink/renderer/core/dom/events/event.h"
 #include "third_party/blink/renderer/core/dom/shadow_root.h"
 #include "third_party/blink/renderer/core/events/keyboard_event.h"
@@ -249,9 +248,8 @@ void FileInputType::SetValue(const String&,
     return;
 
   file_list_->clear();
-  GetElement().SetNeedsStyleRecalc(
-      kSubtreeStyleChange,
-      StyleChangeReasonForTracing::Create(style_change_reason::kControlValue));
+  if (auto* layout_object = GetElement().GetLayoutObject())
+    layout_object->SetShouldDoFullPaintInvalidation();
   GetElement().SetNeedsValidityCheck();
 }
 

third_party/blink/renderer/core/layout/layout_file_upload_control.cc

@@ -38,22 +38,12 @@ const int kDefaultWidthNumChars = 34;
 const int kButtonShadowHeight = 2;
 
 LayoutFileUploadControl::LayoutFileUploadControl(HTMLInputElement* input)
-    : LayoutBlockFlow(input) {}
-
-LayoutFileUploadControl::~LayoutFileUploadControl() = default;
-
-void LayoutFileUploadControl::UpdateFromElement() {
-  auto* input = To<HTMLInputElement>(GetNode());
+    : LayoutBlockFlow(input) {
   DCHECK_EQ(input->type(), input_type_names::kFile);
-
-  // This only supports clearing out the files, but that's OK because for
-  // security reasons that's the only change the DOM is allowed to make.
-  FileList* files = input->files();
-  DCHECK(files);
-  if (files && files->IsEmpty())
-    SetShouldDoFullPaintInvalidation();
 }
 
+LayoutFileUploadControl::~LayoutFileUploadControl() = default;
+
 int LayoutFileUploadControl::MaxFilenameWidth() const {
   int upload_button_width =
       (UploadButton() && UploadButton()->GetLayoutBox())

third_party/blink/renderer/core/layout/layout_file_upload_control.h

@@ -62,7 +62,6 @@ class CORE_EXPORT LayoutFileUploadControl final : public LayoutBlockFlow {
   const char* GetName() const override { return "LayoutFileUploadControl"; }
 
  private:
-  void UpdateFromElement() override;
   void ComputeIntrinsicLogicalWidths(
       LayoutUnit& min_logical_width,
       LayoutUnit& max_logical_width) const override;