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

ui/events/event.cc

Index: ui/events/event.cc
diff --git a/ui/events/event.cc b/ui/events/event.cc
index d0966da00847a13bcfe64258596a445fa57bd0e4..a0a6c9b851e3c1d3f74dd3e6151a4bd5d499000c 100644
--- a/ui/events/event.cc
+++ b/ui/events/event.cc
@@ -526,19 +526,17 @@ TouchEvent::TouchEvent(const base::NativeEvent& 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,
@@ -552,7 +550,7 @@ TouchEvent::TouchEvent(EventType type,
       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);
 }
 
@@ -572,7 +570,7 @@ TouchEvent::TouchEvent(EventType type,
       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();
 }
@@ -581,8 +579,11 @@ 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(