Refactor ScrollableArea::setScrollPosition.

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/frame/RootFrameViewport.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/ScrollAlignment.h"
 #include "core/layout/ScrollAnchor.h"
 #include "platform/geometry/DoubleRect.h"
@@ skipping 189 matching lines @@
       viewRectInContent, rectInContent, alignX, alignY);
   if (targetViewport != viewRectInContent)
     setScrollPosition(DoublePoint(targetViewport.x(), targetViewport.y()),
                       scrollType);
 
   // RootFrameViewport only changes the viewport relative to the document so we can't change the input
   // rect's location relative to the document origin.
   return rectInContent;
 }
 
-void RootFrameViewport::setScrollOffset(const DoublePoint& offset,
-                                        ScrollType scrollType) {
-  distributeScrollBetweenViewports(DoublePoint(offset), scrollType,
+void RootFrameViewport::updateScrollPosition(const DoublePoint& position,
+                                             ScrollType scrollType) {
+  distributeScrollBetweenViewports(DoublePoint(position), scrollType,
                                    ScrollBehaviorInstant, VisualViewport);
 }
 
 void RootFrameViewport::distributeScrollBetweenViewports(
-    const DoublePoint& offset,
+    const DoublePoint& position,
     ScrollType scrollType,
     ScrollBehavior behavior,
     ViewportToScrollFirst scrollFirst) {
   // Make sure we use the scroll positions as reported by each viewport's ScrollAnimatorBase, since its
   // ScrollableArea's position may have the fractional part truncated off.
   DoublePoint oldPosition = scrollOffsetFromScrollAnimators();
 
-  DoubleSize delta = offset - oldPosition;
+  DoubleSize delta = position - oldPosition;
 
   if (delta.isZero())
     return;
 
   ScrollableArea& primary =
       scrollFirst == VisualViewport ? visualViewport() : layoutViewport();
   ScrollableArea& secondary =
       scrollFirst == VisualViewport ? layoutViewport() : visualViewport();
 
   DoublePoint targetPosition = primary.clampScrollPosition(
@@ skipping 188 matching lines @@
   visualViewport().clearScrollAnimators();
 }
 
 DEFINE_TRACE(RootFrameViewport) {
   visitor->trace(m_visualViewport);
   visitor->trace(m_layoutViewport);
   ScrollableArea::trace(visitor);
 }
 
 }  // namespace blink