Revert of Implement Element.scrollIntoView for scroll-behavior: smooth.

third_party/WebKit/Source/platform/scroll/ScrollableArea.h

Index: third_party/WebKit/Source/platform/scroll/ScrollableArea.h
diff --git a/third_party/WebKit/Source/platform/scroll/ScrollableArea.h b/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
index 728ac9b5de9481f28e3750f2d6f995f0939b591b..a84fe5c645f4d5abb3090b8f4208716afac456f0 100644
--- a/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
+++ b/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
@@ -53,7 +53,6 @@
 struct ScrollAlignment;
 class ScrollAnchor;
 class ScrollAnimatorBase;
-class SmoothScrollSequencer;
 class CompositorAnimationTimeline;
 
 enum IncludeScrollbarsInRect {
@@ -77,10 +76,6 @@
   }
 
   virtual PlatformChromeClient* GetChromeClient() const { return 0; }
-
-  virtual SmoothScrollSequencer* GetSmoothScrollSequencer() const {
-    return nullptr;
-  }
 
   virtual ScrollResult UserScroll(ScrollGranularity, const ScrollOffset&);
 
@@ -104,7 +99,6 @@
   virtual LayoutRect ScrollIntoView(const LayoutRect& rect_in_content,
                                     const ScrollAlignment& align_x,
                                     const ScrollAlignment& align_y,
-                                    bool is_smooth,
                                     ScrollType = kProgrammaticScroll);
 
   static bool ScrollBehaviorFromString(const String&, ScrollBehavior&);