Don't refcount tracking id -> slot id mapping.

ui/events/event.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/events/event.h"
 
 #if defined(USE_X11)
 #include <X11/extensions/XInput2.h>
 #include <X11/keysym.h>
 #include <X11/Xlib.h>
@@ skipping 508 matching lines @@
 // TouchEvent
 
 TouchEvent::TouchEvent(const base::NativeEvent& native_event)
     : LocatedEvent(native_event),
       touch_id_(GetTouchId(native_event)),
       unique_event_id_(get_next_touch_event_id()),
       radius_x_(GetTouchRadiusX(native_event)),
       radius_y_(GetTouchRadiusY(native_event)),
       rotation_angle_(GetTouchAngle(native_event)),
       force_(GetTouchForce(native_event)),
-      may_cause_scrolling_(false) {
-  latency()->AddLatencyNumberWithTimestamp(
-      INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
-      0,
-      0,
-      base::TimeTicks::FromInternalValue(time_stamp().ToInternalValue()),
-      1);
+      should_remove_native_touch_id_mapping_(false) {
+  if (type() == ET_TOUCH_RELEASED || type() == ET_TOUCH_CANCELLED)
+    should_remove_native_touch_id_mapping_ = true;
 
   latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
   fixRotationAngle();

[sadrul, 2015/01/26 18:49:46]

We should call this FixRotationAngle()
(https://codereview.chromium.org/800163005/diff/140001/ui/events/event.h#newco...).
Mind fixing this up?

[tdresser, 2015/01/27 21:43:05]

Done.

 
-  if (type() == ET_TOUCH_PRESSED)
-    IncrementTouchIdRefCount(native_event);
+  latency()->AddLatencyNumberWithTimestamp(
+      INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT, 0, 0,
+      base::TimeTicks::FromInternalValue(time_stamp().ToInternalValue()), 1);
+  latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
 }
 
 TouchEvent::TouchEvent(EventType type,
                        const gfx::PointF& location,
                        int touch_id,
                        base::TimeDelta time_stamp)
     : LocatedEvent(type, location, location, time_stamp, 0),
       touch_id_(touch_id),
       unique_event_id_(get_next_touch_event_id()),
       radius_x_(0.0f),
       radius_y_(0.0f),
       rotation_angle_(0.0f),
       force_(0.0f),
-      may_cause_scrolling_(false) {
+      should_remove_native_touch_id_mapping_(false) {
   latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
 }
 
 TouchEvent::TouchEvent(EventType type,
                        const gfx::PointF& location,
                        int flags,
                        int touch_id,
                        base::TimeDelta time_stamp,
                        float radius_x,
                        float radius_y,
                        float angle,
                        float force)
     : LocatedEvent(type, location, location, time_stamp, flags),
       touch_id_(touch_id),
       unique_event_id_(get_next_touch_event_id()),
       radius_x_(radius_x),
       radius_y_(radius_y),
       rotation_angle_(angle),
       force_(force),
-      may_cause_scrolling_(false) {
+      should_remove_native_touch_id_mapping_(false) {
   latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
   fixRotationAngle();
 }
 
 TouchEvent::~TouchEvent() {
   // In ctor TouchEvent(native_event) we call GetTouchId() which in X11
   // platform setups the tracking_id to slot mapping. So in dtor here,
   // if this touch event is a release event, we clear the mapping accordingly.
-  if (HasNativeEvent())
-    ClearTouchIdIfReleased(native_event());
+  if (should_remove_native_touch_id_mapping_) {
+    DCHECK(type() == ET_TOUCH_RELEASED || type() == ET_TOUCH_CANCELLED);
+    if (type() == ET_TOUCH_RELEASED || type() == ET_TOUCH_CANCELLED)
+      ClearTouchIdIfReleased(native_event());
+  }
 }
 
 void TouchEvent::UpdateForRootTransform(
     const gfx::Transform& inverted_root_transform) {
   LocatedEvent::UpdateForRootTransform(inverted_root_transform);
   gfx::DecomposedTransform decomp;
   bool success = gfx::DecomposeTransform(&decomp, inverted_root_transform);
   DCHECK(success);
   if (decomp.scale[0])
     radius_x_ *= decomp.scale[0];
@@ skipping 377 matching lines @@
                    gfx::PointF(x, y),
                    time_stamp,
                    flags | EF_FROM_TOUCH),
       details_(details) {
 }
 
 GestureEvent::~GestureEvent() {
 }
 
 }  // namespace ui