Implemented smooth scrolling using xinput2 in X11.

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

Index: chrome/browser/ui/views/frame/browser_root_view.h
diff --git a/chrome/browser/ui/views/frame/browser_root_view.h b/chrome/browser/ui/views/frame/browser_root_view.h
index e2678fdab70cde1832910fb48cd3958da4c83ec5..312473823cf8ec7ba41b18437cf800bfd6dd9a25 100644
--- a/chrome/browser/ui/views/frame/browser_root_view.h
+++ b/chrome/browser/ui/views/frame/browser_root_view.h
@@ -40,6 +40,7 @@ class BrowserRootView : public views::internal::RootView {
   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:
@@ -69,6 +70,11 @@ class BrowserRootView : public views::internal::RootView {
   // 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);
 };