x11: Use kernel timestamps for touch events (if available).

ui/base/x/valuators.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.
 
 #include "ui/base/x/valuators.h"
 
 #include <X11/extensions/XInput2.h>
 
 #include "base/memory/singleton.h"
 #include "ui/base/touch/touch_factory.h"
 #include "ui/base/x/x11_util.h"
 
 namespace {
 
 #define AXIS_LABEL_ABS_MT_TOUCH_MAJOR "Abs MT Touch Major"
 #define AXIS_LABEL_ABS_MT_TOUCH_MINOR "Abs MT Touch Minor"
 #define AXIS_LABEL_ABS_MT_ORIENTATION "Abs MT Orientation"
 #define AXIS_LABEL_ABS_MT_PRESSURE    "Abs MT Pressure"
 #define AXIS_LABEL_ABS_MT_SLOT_ID     "Abs MT Slot ID"
 #define AXIS_LABEL_ABS_MT_TRACKING_ID "Abs MT Tracking ID"
+#define AXIS_LABEL_TOUCH_TIMESTAMP    "Touch Timestamp"
 
 // Given the Valuator, return the correspoding XIValuatorClassInfo using
 // the X device information through Atom name matching.
 XIValuatorClassInfo* FindValuator(Display* display,
                                   XIDeviceInfo* info,
                                   ui::ValuatorTracker::Valuator val) {
   // Lookup table for mapping Valuator to Atom string used in X.
   // A full set of Atom strings can be found at xserver-properties.h.
   static struct {
     ui::ValuatorTracker::Valuator val;
     Atom atom;
   } kValuatorAtom[] = {
     { ui::ValuatorTracker::VAL_TOUCH_MAJOR,
       XInternAtom(ui::GetXDisplay(), AXIS_LABEL_ABS_MT_TOUCH_MAJOR, false) },
     { ui::ValuatorTracker::VAL_TOUCH_MINOR,
       XInternAtom(ui::GetXDisplay(), AXIS_LABEL_ABS_MT_TOUCH_MINOR, false) },
     { ui::ValuatorTracker::VAL_ORIENTATION,
       XInternAtom(ui::GetXDisplay(), AXIS_LABEL_ABS_MT_ORIENTATION, false) },
     { ui::ValuatorTracker::VAL_PRESSURE,
       XInternAtom(ui::GetXDisplay(), AXIS_LABEL_ABS_MT_PRESSURE, false) },
 #if !defined(USE_XI2_MT)
     // For Slot ID, See this chromeos revision: http://git.chromium.org/gitweb/?
     //        p=chromiumos/overlays/chromiumos-overlay.git;
     //        a=commit;h=9164d0a75e48c4867e4ef4ab51f743ae231c059a
     { ui::ValuatorTracker::VAL_SLOT_ID,
       XInternAtom(ui::GetXDisplay(), AXIS_LABEL_ABS_MT_SLOT_ID, false) },
 #endif
     { ui::ValuatorTracker::VAL_TRACKING_ID,
       XInternAtom(ui::GetXDisplay(), AXIS_LABEL_ABS_MT_TRACKING_ID, false) },
+    { ui::ValuatorTracker::VAL_TOUCH_RAW_TIMESTAMP,
+      XInternAtom(ui::GetXDisplay(), AXIS_LABEL_TOUCH_TIMESTAMP, false) },
     { ui::ValuatorTracker::VAL_LAST_ENTRY, None },
   };
 
   Atom atom = None;
 
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kValuatorAtom); i++) {
     if (val == kValuatorAtom[i].val) {
       atom = kValuatorAtom[i].atom;
       break;
     }
@@ skipping 114 matching lines @@
         valuator_max_[info->deviceid][j] = valuator->max;
       }
     }
   }
 
   if (info_list)
     XIFreeDeviceInfo(info_list);
 }
 
 }  // namespace ui