Use float for scroll offset.

third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 159 matching lines @@
   IntRect scrollCornerRect() const override { return IntRect(); }
   int visibleWidth() const override { return 10; }
   int visibleHeight() const override { return 10; }
   IntSize contentsSize() const override { return IntSize(100, 100); }
   bool scrollbarsCanBeActive() const override { return false; }
   IntRect scrollableAreaBoundingBox() const override { return IntRect(); }
   void scrollControlWasSetNeedsPaintInvalidation() override {}
   bool userInputScrollable(ScrollbarOrientation) const override { return true; }
   bool shouldPlaceVerticalScrollbarOnLeft() const override { return false; }
   int pageStep(ScrollbarOrientation) const override { return 0; }
-  IntPoint minimumScrollPosition() const override { return IntPoint(); }
-  IntPoint maximumScrollPosition() const override {
-    return IntPoint(contentsSize().width() - visibleWidth(),
-                    contentsSize().height() - visibleHeight());
+  IntSize minimumScrollOffsetInt() const override { return IntSize(); }
+  IntSize maximumScrollOffsetInt() const override {
+    return contentsSize() - IntSize(visibleWidth(), visibleHeight());
   }
 
-  void updateScrollPosition(const DoublePoint& position, ScrollType) override {
-    m_scrollPosition = position;
+  void updateScrollOffset(const ScrollOffset& offset, ScrollType) override {
+    m_scrollOffset = offset;
   }
-  DoublePoint scrollPositionDouble() const override { return m_scrollPosition; }
-  IntPoint scrollPosition() const override {
-    return flooredIntPoint(m_scrollPosition);
+  ScrollOffset scrollOffset() const override { return m_scrollOffset; }
+  IntSize scrollOffsetInt() const override {
+    return flooredIntSize(m_scrollOffset);
   }
 
   DEFINE_INLINE_VIRTUAL_TRACE() { ScrollableArea::trace(visitor); }
 
  private:
-  DoublePoint m_scrollPosition;
+  ScrollOffset m_scrollOffset;
 };
 
 TEST_F(GraphicsLayerTest, applyScrollToScrollableArea) {
   FakeScrollableArea* scrollableArea = FakeScrollableArea::create();
   m_graphicsLayer->setScrollableArea(scrollableArea, false);
 
-  WebDoublePoint scrollPosition(7, 9);
-  m_platformLayer->setScrollPositionDouble(scrollPosition);
+  WebFloatSize scrollOffset(7, 9);
+  m_platformLayer->setScrollOffset(scrollOffset);
   m_graphicsLayer->didScroll();
 
-  EXPECT_FLOAT_EQ(scrollPosition.x, scrollableArea->scrollPositionDouble().x());
-  EXPECT_FLOAT_EQ(scrollPosition.y, scrollableArea->scrollPositionDouble().y());
+  EXPECT_FLOAT_EQ(scrollOffset.width, scrollableArea->scrollOffset().width());
+  EXPECT_FLOAT_EQ(scrollOffset.height, scrollableArea->scrollOffset().height());
 }
 
 }  // namespace blink