Use float for scroll offset.

third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm

Index: third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
diff --git a/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm b/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
index 4cbe74040d282f878adfc65b47b59bbfa80e2871..47f815a1872c6443fb2be4ac52f30fec8a6a5cfa 100644
--- a/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
+++ b/third_party/WebKit/Source/platform/mac/ScrollAnimatorMac.mm
@@ -45,8 +45,7 @@
 using namespace blink;
 
 static bool supportsUIStateTransitionProgress() {
-  // FIXME: This is temporary until all platforms that support ScrollbarPainter
-  // support this part of the API.
+  // FIXME: This is temporary until all platforms that support ScrollbarPainter support this part of the API.
   static bool globalSupportsUIStateTransitionProgress =
       [NSClassFromString(@"NSScrollerImp")
           instancesRespondToSelector:@selector(mouseEnteredScroller)];
@@ -123,14 +122,15 @@ static NSSize abs(NSSize size) {
   if (!_animator)
     return NSZeroRect;
 
-  blink::FloatPoint currentPosition = _animator->currentPosition();
-  return NSMakeRect(currentPosition.x(), currentPosition.y(), 0, 0);
+  blink::ScrollOffset currentOffset = _animator->currentOffset();
+  return NSMakeRect(currentOffset.width(), currentOffset.height(), 0, 0);
 }
 
 - (void)_immediateScrollToPoint:(NSPoint)newPosition {
   if (!_animator)
     return;
-  _animator->immediateScrollToPointForScrollAnimation(newPosition);
+  _animator->immediateScrollToOffsetForScrollAnimation(
+      toScrollOffset(newPosition));
 }
 
 - (NSPoint)_pixelAlignProposedScrollPosition:(NSPoint)newOrigin {
@@ -222,11 +222,11 @@ static NSSize abs(NSSize size) {
   else
     scrollbar = _scrollableArea->verticalScrollbar();
 
-  // It is possible to have a null scrollbar here since it is possible for this
-  // delegate method to be called between the moment when a scrollbar has been
-  // set to 0 and the moment when its destructor has been called. We should
-  // probably de-couple some of the clean-up work in
-  // ScrollbarThemeMac::unregisterScrollbar() to avoid this issue.
+  // It is possible to have a null scrollbar here since it is possible for this delegate
+  // method to be called between the moment when a scrollbar has been set to 0 and the
+  // moment when its destructor has been called. We should probably de-couple some
+  // of the clean-up work in ScrollbarThemeMac::unregisterScrollbar() to avoid this
+  // issue.
   if (!scrollbar)
     return NSZeroPoint;
 
@@ -250,9 +250,8 @@ static NSSize abs(NSSize size) {
 - (void)scrollerImpPair:(id)scrollerImpPair
     updateScrollerStyleForNewRecommendedScrollerStyle:
         (NSScrollerStyle)newRecommendedScrollerStyle {
-  // Chrome has a single process mode which is used for testing on Mac. In that
-  // mode, WebKit runs on a thread in the browser process. This notification is
-  // called by the OS on the main thread in the browser process, and not on the
+  // Chrome has a single process mode which is used for testing on Mac. In that mode, WebKit runs on a thread in the
+  // browser process. This notification is called by the OS on the main thread in the browser process, and not on the
   // the WebKit thread. Better to not update the style than crash.
   // http://crbug.com/126514
   if (!isMainThread())
@@ -280,10 +279,10 @@ enum FeatureToAnimate {
 
 namespace blink {
 
-// This class is used to drive the animation timer for
-// BlinkScrollbarPartAnimation objects. This is used instead of NSAnimation
-// because CoreAnimation establishes connections to the WindowServer, which
-// should not be done in a sandboxed renderer process.
+// This class is used to drive the animation timer for BlinkScrollbarPartAnimation
+// objects. This is used instead of NSAnimation because CoreAnimation
+// establishes connections to the WindowServer, which should not be done in a
+// sandboxed renderer process.
 class BlinkScrollbarPartAnimationTimer {
  public:
   BlinkScrollbarPartAnimationTimer(BlinkScrollbarPartAnimation* animation,
@@ -498,8 +497,8 @@ class BlinkScrollbarPartAnimationTimer {
                        part:(blink::ScrollbarPart)part
              animateAlphaTo:(CGFloat)newAlpha
                    duration:(NSTimeInterval)duration {
-  // If the user has scrolled the page, then the scrollbars must be animated
-  // here.  This overrides the early returns.
+  // If the user has scrolled the page, then the scrollbars must be animated here.
+  // This overrides the early returns.
   bool mustAnimate = [self scrollAnimator].haveScrolledSincePageLoad();
 
   if ([self scrollAnimator].scrollbarPaintTimerIsActive() && !mustAnimate)
@@ -583,8 +582,7 @@ class BlinkScrollbarPartAnimationTimer {
 
   ScrollbarPainter scrollbarPainter = (ScrollbarPainter)scrollerImp;
 
-  // UIStateTransition always animates to 1. In case an animation is in progress
-  // this avoids a hard transition.
+  // UIStateTransition always animates to 1. In case an animation is in progress this avoids a hard transition.
   [scrollbarPainter
       setUiStateTransitionProgress:1 - [scrollerImp uiStateTransitionProgress]];
 
@@ -596,8 +594,7 @@ class BlinkScrollbarPartAnimationTimer {
                 animateTo:1.0
                  duration:duration]);
   else {
-    // If we don't need to initialize the animation, just reset the values in
-    // case they have changed.
+    // If we don't need to initialize the animation, just reset the values in case they have changed.
     [_uiStateTransitionAnimation.get()
         setStartValue:[scrollbarPainter uiStateTransitionProgress]];
     [_uiStateTransitionAnimation.get() setEndValue:1.0];
@@ -618,8 +615,7 @@ class BlinkScrollbarPartAnimationTimer {
 
   ScrollbarPainter scrollbarPainter = (ScrollbarPainter)scrollerImp;
 
-  // ExpansionTransition always animates to 1. In case an animation is in
-  // progress this avoids a hard transition.
+  // ExpansionTransition always animates to 1. In case an animation is in progress this avoids a hard transition.
   [scrollbarPainter
       setExpansionTransitionProgress:1 -
                                      [scrollerImp expansionTransitionProgress]];
@@ -632,8 +628,7 @@ class BlinkScrollbarPartAnimationTimer {
                 animateTo:1.0
                  duration:duration]);
   } else {
-    // If we don't need to initialize the animation, just reset the values in
-    // case they have changed.
+    // If we don't need to initialize the animation, just reset the values in case they have changed.
     [_expansionTransitionAnimation.get()
         setStartValue:[scrollbarPainter uiStateTransitionProgress]];
     [_expansionTransitionAnimation.get() setEndValue:1.0];
@@ -644,17 +639,15 @@ class BlinkScrollbarPartAnimationTimer {
 
 - (void)scrollerImp:(id)scrollerImp
     overlayScrollerStateChangedTo:(NSUInteger)newOverlayScrollerState {
-  // The names of these states are based on their observed behavior, and are not
-  // based on documentation.
+  // The names of these states are based on their observed behavior, and are not based on documentation.
   enum {
     NSScrollerStateInvisible = 0,
     NSScrollerStateKnob = 1,
     NSScrollerStateExpanded = 2
   };
-  // We do not receive notifications about the thumb un-expanding when the
-  // scrollbar fades away. Ensure that we re-paint the thumb the next time that
-  // we transition away from being invisible, so that the thumb doesn't stick
-  // in an expanded state.
+  // We do not receive notifications about the thumb un-expanding when the scrollbar fades away. Ensure
+  // that we re-paint the thumb the next time that we transition away from being invisible, so that
+  // the thumb doesn't stick in an expanded state.
   if (newOverlayScrollerState == NSScrollerStateExpanded) {
     _hasExpandedSinceInvisible = YES;
   } else if (newOverlayScrollerState != NSScrollerStateInvisible &&
@@ -733,7 +726,7 @@ void ScrollAnimatorMac::dispose() {
 }
 
 ScrollResult ScrollAnimatorMac::userScroll(ScrollGranularity granularity,
-                                           const FloatSize& delta) {
+                                           const ScrollOffset& delta) {
   m_haveScrolledSincePageLoad = true;
 
   if (!m_scrollableArea->scrollAnimatorEnabled())
@@ -742,66 +735,67 @@ ScrollResult ScrollAnimatorMac::userScroll(ScrollGranularity granularity,
   if (granularity == ScrollByPixel || granularity == ScrollByPrecisePixel)
     return ScrollAnimatorBase::userScroll(granularity, delta);
 
-  FloatSize consumedDelta = computeDeltaToConsume(delta);
-  FloatPoint newPos = m_currentPos + consumedDelta;
-  if (m_currentPos == newPos)
+  ScrollOffset consumedDelta = computeDeltaToConsume(delta);
+  ScrollOffset newOffset = m_currentOffset + consumedDelta;
+  if (m_currentOffset == newOffset)
     return ScrollResult();
 
   // Prevent clobbering an existing animation on an unscrolled axis.
   if ([m_scrollAnimationHelper.get() _isAnimating]) {
     NSPoint targetOrigin = [m_scrollAnimationHelper.get() targetOrigin];
     if (!delta.width())
-      newPos.setX(targetOrigin.x);
+      newOffset.setWidth(targetOrigin.x);
     if (!delta.height())
-      newPos.setY(targetOrigin.y);
+      newOffset.setHeight(targetOrigin.y);
   }
 
-  NSPoint newPoint = NSMakePoint(newPos.x(), newPos.y());
+  NSPoint newPoint = NSMakePoint(newOffset.width(), newOffset.height());
   [m_scrollAnimationHelper.get() scrollToPoint:newPoint];
 
-  // TODO(bokan): This has different semantics on ScrollResult than
-  // ScrollAnimator, which only returns unused delta if there's no animation
-  // and we don't start one.
+  // TODO(bokan): This has different semantics on ScrollResult than ScrollAnimator,
+  // which only returns unused delta if there's no animation and we don't start one.
   return ScrollResult(consumedDelta.width(), consumedDelta.height(),
                       delta.width() - consumedDelta.width(),
                       delta.height() - consumedDelta.height());
 }
 
 void ScrollAnimatorMac::scrollToOffsetWithoutAnimation(
-    const FloatPoint& offset) {
+    const ScrollOffset& offset) {
   [m_scrollAnimationHelper.get() _stopRun];
   immediateScrollTo(offset);
 }
 
-FloatPoint ScrollAnimatorMac::adjustScrollPositionIfNecessary(
-    const FloatPoint& position) const {
-  IntPoint minPos = m_scrollableArea->minimumScrollPosition();
-  IntPoint maxPos = m_scrollableArea->maximumScrollPosition();
+ScrollOffset ScrollAnimatorMac::adjustScrollOffsetIfNecessary(
+    const ScrollOffset& offset) const {
+  ScrollOffset minOffset = m_scrollableArea->minimumScrollOffset();
+  ScrollOffset maxOffset = m_scrollableArea->maximumScrollOffset();
 
-  float newX = clampTo<float, float>(position.x(), minPos.x(), maxPos.x());
-  float newY = clampTo<float, float>(position.y(), minPos.y(), maxPos.y());
+  float newX = clampTo<float, float>(offset.width(), minOffset.width(),
+                                     maxOffset.width());
+  float newY = clampTo<float, float>(offset.height(), minOffset.height(),
+                                     maxOffset.height());
 
-  return FloatPoint(newX, newY);
+  return ScrollOffset(newX, newY);
 }
 
-void ScrollAnimatorMac::immediateScrollTo(const FloatPoint& newPosition) {
-  FloatPoint adjustedPosition = adjustScrollPositionIfNecessary(newPosition);
+void ScrollAnimatorMac::immediateScrollTo(const ScrollOffset& newOffset) {
+  ScrollOffset adjustedOffset = adjustScrollOffsetIfNecessary(newOffset);
 
-  bool positionChanged = adjustedPosition != m_currentPos;
-  if (!positionChanged && !getScrollableArea()->scrollOriginChanged())
+  bool offsetChanged = adjustedOffset != m_currentOffset;
+  if (!offsetChanged && !getScrollableArea()->scrollOriginChanged())
     return;
 
-  FloatSize delta = adjustedPosition - m_currentPos;
+  ScrollOffset delta = adjustedOffset - m_currentOffset;
 
-  m_currentPos = adjustedPosition;
+  m_currentOffset = adjustedOffset;
   notifyContentAreaScrolled(delta);
-  notifyPositionChanged();
+  notifyOffsetChanged();
 }
 
-void ScrollAnimatorMac::immediateScrollToPointForScrollAnimation(
-    const FloatPoint& newPosition) {
+void ScrollAnimatorMac::immediateScrollToOffsetForScrollAnimation(
+    const ScrollOffset& newOffset) {
   ASSERT(m_scrollAnimationHelper);
-  immediateScrollTo(newPosition);
+  immediateScrollTo(newOffset);
 }
 
 void ScrollAnimatorMac::contentAreaWillPaint() const {
@@ -947,19 +941,17 @@ bool ScrollAnimatorMac::shouldScrollbarParticipateInHitTesting(
   if (ScrollbarThemeMac::recommendedScrollerStyle() != NSScrollerStyleOverlay)
     return true;
 
-  // Overlay scrollbars should participate in hit testing whenever they are at
-  // all visible.
+  // Overlay scrollbars should participate in hit testing whenever they are at all visible.
   ScrollbarPainter painter = scrollbarPainterForScrollbar(scrollbar);
   if (!painter)
     return false;
   return [painter knobAlpha] > 0;
 }
 
-void ScrollAnimatorMac::notifyContentAreaScrolled(const FloatSize& delta) {
-  // This function is called when a page is going into the page cache, but the
-  // page isn't really scrolling in that case. We should only pass the message
-  // on to the ScrollbarPainterController when we're really scrolling on an
-  // active page.
+void ScrollAnimatorMac::notifyContentAreaScrolled(const ScrollOffset& delta) {
+  // This function is called when a page is going into the page cache, but the page
+  // isn't really scrolling in that case. We should only pass the message on to the
+  // ScrollbarPainterController when we're really scrolling on an active page.
   if (getScrollableArea()->scrollbarsCanBeActive())
     sendContentAreaScrolledSoon(delta);
 }
@@ -981,8 +973,8 @@ void ScrollAnimatorMac::cancelAnimation() {
 }
 
 void ScrollAnimatorMac::handleWheelEventPhase(PlatformWheelEventPhase phase) {
-  // This may not have been set to true yet if the wheel event was handled by
-  // the ScrollingTree, so set it to true here.
+  // This may not have been set to true yet if the wheel event was handled by the ScrollingTree,
+  // So set it to true here.
   m_haveScrolledSincePageLoad = true;
 
   if (phase == PlatformWheelEventPhaseBegan)
@@ -1022,9 +1014,9 @@ void ScrollAnimatorMac::updateScrollerStyle() {
         setVerticalScrollerImp:newVerticalPainter];
     macTheme->setNewPainterForScrollbar(*verticalScrollbar, newVerticalPainter);
 
-    // The different scrollbar styles have different thicknesses, so we must
-    // re-set the frameRect to the new thickness, and the re-layout below will
-    // ensure the position and length are properly updated.
+    // The different scrollbar styles have different thicknesses, so we must re-set the
+    // frameRect to the new thickness, and the re-layout below will ensure the offset
+    // and length are properly updated.
     int thickness =
         macTheme->scrollbarThickness(verticalScrollbar->controlSize());
     verticalScrollbar->setFrameRect(IntRect(0, 0, thickness, thickness));
@@ -1046,17 +1038,16 @@ void ScrollAnimatorMac::updateScrollerStyle() {
     macTheme->setNewPainterForScrollbar(*horizontalScrollbar,
                                         newHorizontalPainter);
 
-    // The different scrollbar styles have different thicknesses, so we must
-    // re-set the frameRect to the new thickness, and the re-layout below will
-    // ensure the position and length are properly updated.
+    // The different scrollbar styles have different thicknesses, so we must re-set the
+    // frameRect to the new thickness, and the re-layout below will ensure the offset
+    // and length are properly updated.
     int thickness =
         macTheme->scrollbarThickness(horizontalScrollbar->controlSize());
     horizontalScrollbar->setFrameRect(IntRect(0, 0, thickness, thickness));
   }
 
-  // If m_needsScrollerStyleUpdate is true, then the page is restoring from the
-  // page cache, and a relayout will happen on its own. Otherwise, we must
-  // initiate a re-layout ourselves.
+  // If m_needsScrollerStyleUpdate is true, then the page is restoring from the page cache, and
+  // a relayout will happen on its own. Otherwise, we must initiate a re-layout ourselves.
   if (!m_needsScrollerStyleUpdate)
     getScrollableArea()->scrollbarStyleChanged();
 
@@ -1078,14 +1069,13 @@ void ScrollAnimatorMac::stopScrollbarPaintTimer() {
 }
 
 void ScrollAnimatorMac::initialScrollbarPaintTask() {
-  // To force the scrollbars to flash, we have to call hide first. Otherwise,
-  // the ScrollbarPainterController might think that the scrollbars are already
-  // showing and bail early.
+  // To force the scrollbars to flash, we have to call hide first. Otherwise, the ScrollbarPainterController
+  // might think that the scrollbars are already showing and bail early.
   [m_scrollbarPainterController.get() hideOverlayScrollers];
   [m_scrollbarPainterController.get() flashScrollers];
 }
 
-void ScrollAnimatorMac::sendContentAreaScrolledSoon(const FloatSize& delta) {
+void ScrollAnimatorMac::sendContentAreaScrolledSoon(const ScrollOffset& delta) {
   m_contentAreaScrolledTimerScrollDelta = delta;
 
   if (!m_sendContentAreaScrolledTaskFactory->isPending())
@@ -1102,7 +1092,7 @@ void ScrollAnimatorMac::sendContentAreaScrolledTask() {
                                                .width(),
                                            m_contentAreaScrolledTimerScrollDelta
                                                .height())];
-    m_contentAreaScrolledTimerScrollDelta = FloatSize();
+    m_contentAreaScrolledTimerScrollDelta = ScrollOffset();
   } else
     [m_scrollbarPainterController.get() contentAreaScrolled];
 }