Implement Element.scrollIntoView for scroll-behavior: smooth.

third_party/WebKit/Source/core/frame/LocalFrameView.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 2124 matching lines @@
   }
 }
 
 PlatformChromeClient* LocalFrameView::GetChromeClient() const {
   Page* page = GetFrame().GetPage();
   if (!page)
     return nullptr;
   return &page->GetChromeClient();
 }
 
+SmoothScrollSequencer* LocalFrameView::GetSmoothScrollSequencer() const {
+  Page* page = GetFrame().GetPage();
+  if (!page)
+    return nullptr;
+  return page->GetSmoothScrollSequencer();
+}
+
 void LocalFrameView::ContentsResized() {
   if (frame_->IsMainFrame() && frame_->GetDocument()) {
     if (TextAutosizer* text_autosizer =
             frame_->GetDocument()->GetTextAutosizer())
       text_autosizer->UpdatePageInfoInAllFrames();
   }
 
   ScrollableArea::ContentsResized();
   SetNeedsLayout();
 }
@@ skipping 2469 matching lines @@
   return mode == kScrollbarAuto || mode == kScrollbarAlwaysOn;
 }
 
 bool LocalFrameView::ShouldPlaceVerticalScrollbarOnLeft() const {
   return false;
 }
 
 LayoutRect LocalFrameView::ScrollIntoView(const LayoutRect& rect_in_content,
                                           const ScrollAlignment& align_x,
                                           const ScrollAlignment& align_y,
+                                          bool is_smooth,
                                           ScrollType scroll_type) {
   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 == kProgrammaticScroll);
+      GetSmoothScrollSequencer()->QueueAnimation(this, target_offset);
+    } else {
+      SetScrollOffset(target_offset, scroll_type);
+    }
   }
 
   // Scrolling the LocalFrameView cannot change the input rect's location
   // relative to the document.
   return rect_in_content;
 }
 
 IntRect LocalFrameView::ScrollCornerRect() const {
   IntRect corner_rect;
 
@@ skipping 747 matching lines @@
 void LocalFrameView::SetAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   animation_host_ = std::move(host);
 }
 
 LayoutUnit LocalFrameView::CaretWidth() const {
   return LayoutUnit(GetChromeClient()->WindowToViewportScalar(1));
 }
 
 }  // namespace blink