Implement Element.scrollIntoView for scroll-behavior: smooth.

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 2129 matching lines @@
   }
 }
 
 PlatformChromeClient* FrameView::GetChromeClient() const {
   Page* page = GetFrame().GetPage();
   if (!page)
     return nullptr;
   return &page->GetChromeClient();
 }
 
+SmoothScrollSequencer* FrameView::GetSmoothScrollSequencer() const {
+  Page* page = GetFrame().GetPage();
+  if (!page)
+    return nullptr;
+  return page->GetSmoothScrollSequencer();
+}
+
 void FrameView::ContentsResized() {
   if (frame_->IsMainFrame() && frame_->GetDocument()) {
     if (TextAutosizer* text_autosizer =
             frame_->GetDocument()->GetTextAutosizer())
       text_autosizer->UpdatePageInfoInAllFrames();
   }
 
   ScrollableArea::ContentsResized();
   SetNeedsLayout();
 }
@@ skipping 2468 matching lines @@
   return mode == kScrollbarAuto || mode == kScrollbarAlwaysOn;
 }
 
 bool FrameView::ShouldPlaceVerticalScrollbarOnLeft() const {
   return false;
 }
 
 LayoutRect FrameView::ScrollIntoView(const LayoutRect& rect_in_content,
                                      const ScrollAlignment& align_x,
                                      const ScrollAlignment& align_y,
-                                     ScrollType scroll_type) {
+                                     ScrollType scroll_type,
+                                     bool is_smooth) {
   LayoutRect view_rect(VisibleContentRect());
   LayoutRect expose_rect = ScrollAlignment::GetRectToExpose(
       view_rect, rect_in_content, align_x, align_y);
   if (expose_rect != view_rect) {
-    SetScrollOffset(
-        ScrollOffset(expose_rect.X().ToFloat(), expose_rect.Y().ToFloat()),
-        scroll_type);
+    ScrollOffset target_offset(expose_rect.X().ToFloat(),
+                               expose_rect.Y().ToFloat());
+    if (is_smooth) {
+      DCHECK(scroll_type != kUserScroll);
+      GetSmoothScrollSequencer()->QueueAnimation(this, target_offset);
+    } else {
+      SetScrollOffset(target_offset, scroll_type);
+    }
   }
 
   // Scrolling the FrameView cannot change the input rect's location relative to
   // the document.
   return rect_in_content;
 }
 
 IntRect FrameView::ScrollCornerRect() const {
   IntRect corner_rect;
 
@@ skipping 734 matching lines @@
 void FrameView::SetAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   animation_host_ = std::move(host);
 }
 
 LayoutUnit FrameView::CaretWidth() const {
   return LayoutUnit(GetChromeClient()->WindowToViewportScalar(1));
 }
 
 }  // namespace blink