Implemented smooth scrolling using xinput2 in X11.

chrome/browser/ui/views/frame/browser_root_view.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_ROOT_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_ROOT_VIEW_H_
 
 #include "ui/views/widget/root_view.h"
 
 class BrowserView;
@@ skipping 21 matching lines @@
       int* formats,
       std::set<ui::Clipboard::FormatType>* format_types) override;
   bool AreDropTypesRequired() override;
   bool CanDrop(const ui::OSExchangeData& data) override;
   void OnDragEntered(const ui::DropTargetEvent& event) override;
   int OnDragUpdated(const ui::DropTargetEvent& event) override;
   void OnDragExited() override;
   int OnPerformDrop(const ui::DropTargetEvent& event) override;
   const char* GetClassName() const override;
   bool OnMouseWheel(const ui::MouseWheelEvent& event) override;
+  void OnMouseExited(const ui::MouseEvent& event) override;
 
  private:
   // ui::EventProcessor:
   void OnEventProcessingStarted(ui::Event* event) override;
 
   // Returns true if the event should be forwarded to the tabstrip.
   bool ShouldForwardToTabStrip(const ui::DropTargetEvent& event);
 
   // Converts the event from the hosts coordinate system to the tabstrips
   // coordinate system.
   ui::DropTargetEvent* MapEventToTabStrip(
       const ui::DropTargetEvent& event,
       const ui::OSExchangeData& data);
 
   inline TabStrip* tabstrip() const;
 
   // Returns true if |data| has string contents and the user can "paste and go".
   // If |url| is non-null and the user can "paste and go", |url| is set to the
   // desired destination.
   bool GetPasteAndGoURL(const ui::OSExchangeData& data, GURL* url);
 
   // The BrowserView.
   BrowserView* browser_view_;
 
   // If true, drag and drop events are being forwarded to the tab strip.
   // This is used to determine when to send OnDragEntered and OnDragExited
   // to the tab strip.
   bool forwarding_to_tab_strip_;
 
+  // Used to calculate partial offsets in scrolls that occur for a smooth
+  // scroll device.
+  int scroll_amount_x_;
+  int scroll_amount_y_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserRootView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_ROOT_VIEW_H_