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 924c780768be24a3084d76d12e53be351ce24ebf..d19ab290939ac0fc00ee8c0281f1c1face039d1e 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -26,6 +26,7 @@
 #ifndef FrameView_h
 #define FrameView_h
 
+#include <memory>
 #include "core/CoreExport.h"
 #include "core/dom/DocumentLifecycle.h"
 #include "core/frame/FrameViewAutoSizeInfo.h"
@@ -46,6 +47,7 @@
 #include "platform/geometry/LayoutRect.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/GraphicsLayerClient.h"
+#include "platform/scroll/ProgrammaticScrollCoordinator.h"
 #include "platform/scroll/ScrollTypes.h"
 #include "platform/scroll/Scrollbar.h"
 #include "public/platform/ShapeProperties.h"
@@ -57,7 +59,6 @@
 #include "wtf/HashSet.h"
 #include "wtf/ListHashSet.h"
 #include "wtf/text/WTFString.h"
-#include <memory>
 
 namespace blink {
 
@@ -453,12 +454,16 @@ class CORE_EXPORT FrameView final
   LayoutRect scrollIntoView(const LayoutRect& rectInContent,
                             const ScrollAlignment& alignX,
                             const ScrollAlignment& alignY,
-                            ScrollType = ProgrammaticScroll) override;
+                            ScrollType = ProgrammaticScroll,
+                            bool isSmooth = 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.
   HostWindow* getHostWindow() const;
 
+  ProgrammaticScrollCoordinator* getProgrammaticScrollCoordinator()

[bokan, 2017/03/28 16:29:53]

Please change the name to avoid confusion with the regular ScrollingCoordinator.
They're very unrelated. As I mentioned a while ago, SmoothScrollSequencer or
Scheduler, something along those lines would be more descriptive of what it
does.

[sunyunjia, 2017/04/07 13:53:21]

Done.

+      const override;
+
   typedef HeapHashSet<Member<Widget>> ChildrenWidgetSet;
 
   // Functions for child manipulation and inspection.