Do not pass scrollPosition to updateScrollbars at every callsite

More followup cleanup to the scroll position code. This is a minor
refactoring to push the scroll position double concent into
updateScrollbars since it does not need to be plumbed at every callsite.
scrollPositionDouble has some subtlety (see comment above it) which is
easy to mess up.

Review URL: https://codereview.chromium.org/1758413002

Cr-Commit-Position: refs/heads/master@{#380478}

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

@@ -398,7 +398,7 @@ void FrameView::setFrameRect(const IntRect& newRect)
 
     Widget::setFrameRect(newRect);
 
-    updateScrollbars(scrollOffsetDouble());
+    updateScrollbars();
     frameRectsChanged();
 
     updateScrollableAreaSet();
@@ -506,7 +506,7 @@ void FrameView::setContentsSize(const IntSize& size)
         return;
 
     m_contentsSize = size;
-    updateScrollbars(scrollOffsetDouble());
+    updateScrollbars();
     ScrollableArea::contentsResized();
 
     Page* page = frame().page();
@@ -537,7 +537,7 @@ void FrameView::adjustViewSize()
         // updating scrollbars twice by skipping the call here when the content
         // size does not change.
         if (!m_frame->document()->printing() && size == contentsSize())
-            updateScrollbars(scrollOffsetDouble());
+            updateScrollbars();
     }
 
     setContentsSize(size);
@@ -1009,7 +1009,7 @@ void FrameView::layout()
             }
 
             if (needsScrollbarReconstruction() || scrollOriginChanged())
-                updateScrollbars(scrollOffsetDouble());
+                updateScrollbars();
 
             LayoutSize oldSize = m_size;
 
@@ -2257,7 +2257,7 @@ void FrameView::scrollbarStyleChanged()
         return;
     adjustScrollbarOpacity();
     contentsResized();
-    updateScrollbars(scrollOffsetDouble());
+    updateScrollbars();
     positionScrollbarLayers();
 }
 
@@ -3160,7 +3160,7 @@ void FrameView::setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode ve
     if (!needsUpdate)
         return;
 
-    updateScrollbars(scrollOffsetDouble());
+    updateScrollbars();
 
     if (!layerForScrolling())
         return;
@@ -3270,7 +3270,7 @@ void FrameView::setScrollOffset(const DoublePoint& offset, ScrollType scrollType
 
 void FrameView::windowResizerRectChanged()
 {
-    updateScrollbars(scrollOffsetDouble());
+    updateScrollbars();
 }
 
 bool FrameView::hasOverlayScrollbars() const
@@ -3441,7 +3441,7 @@ bool FrameView::shouldIgnoreOverflowHidden() const
     return m_frame->settings()->ignoreMainFrameOverflowHiddenQuirk() && m_frame->isMainFrame();
 }
 
-void FrameView::updateScrollbars(const DoubleSize& desiredOffset)
+void FrameView::updateScrollbars()
 {
     if (m_frame->settings() && m_frame->settings()->rootLayerScrolls())
         return;
@@ -3450,7 +3450,7 @@ void FrameView::updateScrollbars(const DoubleSize& desiredOffset)
     if (visualViewportSuppliesScrollbars()) {
         setHasHorizontalScrollbar(false);
         setHasVerticalScrollbar(false);
-        setScrollOffsetFromUpdateScrollbars(desiredOffset);
+        setScrollOffsetFromUpdateScrollbars(scrollOffsetDouble());
         return;
     }
 
@@ -3482,7 +3482,7 @@ void FrameView::updateScrollbars(const DoubleSize& desiredOffset)
         updateScrollCorner();
     }
 
-    setScrollOffsetFromUpdateScrollbars(desiredOffset);
+    setScrollOffsetFromUpdateScrollbars(scrollOffsetDouble());
 }
 
 void FrameView::setScrollOffsetFromUpdateScrollbars(const DoubleSize& offset)

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

@@ -619,7 +619,7 @@ protected:
     IntRect adjustScrollbarRectForResizer(const IntRect&, Scrollbar&);
 
     // Called to update the scrollbars to accurately reflect the state of the view.
-    void updateScrollbars(const DoubleSize& desiredOffset);
+    void updateScrollbars();
 
     class InUpdateScrollbarsScope {
         STACK_ALLOCATED();