Implemented smooth scrolling using xinput2 in X11.

ui/base/x/x11_util.cc

 // 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.
 
 // This file defines utility functions for X11 (Linux only). This code has been
 // ported from XCB since we can't use XCB on Ubuntu while its 32-bit support
 // remains woefully incomplete.
 
 #include "ui/base/x/x11_util.h"
 
@@ skipping 353 matching lines @@
     // The |bitmap| contains ARGB image, so just copy it.
     memcpy(image->pixels,
            bitmap->getPixels(),
            bitmap->width() * bitmap->height() * 4);
     bitmap->unlockPixels();
   }
 
   return image;
 }
 
-
-int CoalescePendingMotionEvents(const XEvent* xev,
-                                XEvent* last_event) {
+int CoalescePendingMotionEvents(const XEvent* xev, XEvent* last_event) {
   XIDeviceEvent* xievent = static_cast<XIDeviceEvent*>(xev->xcookie.data);
   int num_coalesced = 0;
   XDisplay* display = xev->xany.display;
   int event_type = xev->xgeneric.evtype;
 
   DCHECK(event_type == XI_Motion || event_type == XI_TouchUpdate);
 
   while (XPending(display)) {
     XEvent next_event;
     XPeekEvent(display, &next_event);
 
     // If we can't get the cookie, abort the check.
     if (!XGetEventData(next_event.xgeneric.display, &next_event.xcookie))
       return num_coalesced;
 
     // If this isn't from a valid device, throw the event away, as
     // that's what the message pump would do. Device events come in pairs
     // with one from the master and one from the slave so there will
     // always be at least one pending.
     if (!ui::TouchFactory::GetInstance()->ShouldProcessXI2Event(&next_event)) {
       XFreeEventData(display, &next_event.xcookie);
       XNextEvent(display, &next_event);
       continue;
     }
 
     if (next_event.type == GenericEvent &&
         next_event.xgeneric.evtype == event_type &&
         !ui::DeviceDataManagerX11::GetInstance()->IsCMTGestureEvent(
-            &next_event)) {
+            &next_event) &&
+        ui::DeviceDataManagerX11::GetInstance()->GetScrollClassEventDetail(
+            &next_event) == SCROLL_TYPE_NO_SCROLL) {
       XIDeviceEvent* next_xievent =
           static_cast<XIDeviceEvent*>(next_event.xcookie.data);
       // Confirm that the motion event is targeted at the same window
       // and that no buttons or modifiers have changed.
       if (xievent->event == next_xievent->event &&
           xievent->child == next_xievent->child &&
           xievent->detail == next_xievent->detail &&
           xievent->buttons.mask_len == next_xievent->buttons.mask_len &&
-          (memcmp(xievent->buttons.mask,
-                  next_xievent->buttons.mask,
+          (memcmp(xievent->buttons.mask, next_xievent->buttons.mask,
                   xievent->buttons.mask_len) == 0) &&
           xievent->mods.base == next_xievent->mods.base &&
           xievent->mods.latched == next_xievent->mods.latched &&
           xievent->mods.locked == next_xievent->mods.locked &&
           xievent->mods.effective == next_xievent->mods.effective) {
         XFreeEventData(display, &next_event.xcookie);
         // Free the previous cookie.
         if (num_coalesced > 0)
           XFreeEventData(display, &last_event->xcookie);
         // Get the event and its cookie data.
@@ skipping 1044 matching lines @@
   if (depth)
     *depth = s_depth;
 }
 #endif
 
 // ----------------------------------------------------------------------------
 // End of x11_util_internal.h
 
 
 }  // namespace ui