Implement Element.scrollIntoView for scroll-behavior: smooth.

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

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index bf4e3dcf3415b0abb31bbf011f057f37693d3023..109d84a1d771f5c8f9af772bd4d64f9ad4b03cde 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -52,6 +52,7 @@
 #include "platform/graphics/GraphicsLayerClient.h"
 #include "platform/scroll/ScrollTypes.h"
 #include "platform/scroll/Scrollbar.h"
+#include "platform/scroll/SmoothScrollSequencer.h"
 #include "platform/wtf/Allocator.h"
 #include "platform/wtf/AutoReset.h"
 #include "platform/wtf/Forward.h"
@@ -475,13 +476,17 @@ class CORE_EXPORT FrameView final
   LayoutRect ScrollIntoView(const LayoutRect& rect_in_content,
                             const ScrollAlignment& align_x,
                             const ScrollAlignment& align_y,
-                            ScrollType = kProgrammaticScroll) override;
+                            ScrollType = kProgrammaticScroll,
+                            bool is_smooth = false) override;
 
   // The window that hosts the FrameView. The FrameView will communicate scrolls
   // and repaints to the host window in the window's coordinate space.
   PlatformChromeClient* GetChromeClient() const;
 
+  SmoothScrollSequencer* GetSmoothScrollSequencer() const override;
+
   typedef HeapHashSet<Member<FrameOrPlugin>> ChildrenSet;
+

[bokan, 2017/05/15 17:15:28]

Nit: remove newline

[sunyunjia, 2017/05/19 16:24:29]

Done.

   typedef HeapHashSet<Member<Scrollbar>> ScrollbarsSet;
 
   // Functions for child manipulation and inspection.