Set the unique_event_id when converting from TouchEvent to WebTouchEvent

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 93 matching lines @@
       Button1Mask | Button2Mask | Button3Mask | Button4Mask | Button5Mask |
       Mod1Mask | Mod2Mask | Mod3Mask | Mod4Mask | Mod5Mask | ShiftMask |
       LockMask | ControlMask | AnyModifier;
   return event && (event->xkey.state & ~kAllStateMask) != 0;
 #else
   return false;
 #endif
 }
 
 unsigned long long get_next_touch_event_id() {
-  static unsigned long long id = 0;
+  // Set the first touch_event_id to 1 because we set id to 0 for other types
+  // of events.
+  static unsigned long long id = 1;
   return id++;

[tdresser, 2015/03/16 12:24:12]

We should check if id has wrapped around, and set it back to 1 if it has.

We should also add a check somewhere (possibly on the renderer side) to ensure
that touch events never have a unique id of 0.

If we are using uint32, we should change this method to return a uint32.

[lanwei, 2015/03/16 19:06:07]

Done.

 }
 
 }  // namespace
 
 namespace ui {
 
 ////////////////////////////////////////////////////////////////////////////////
 // Event
 
 // static
@@ skipping 394 matching lines @@
         gfx::ToRoundedInt(SkMScalarToFloat(offset_.y() * decomp.scale[1])));
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // TouchEvent
 
 TouchEvent::TouchEvent(const base::NativeEvent& native_event)
     : LocatedEvent(native_event),
       touch_id_(GetTouchId(native_event)),
-      unique_event_id_(get_next_touch_event_id()),
+      unique_touch_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),
       should_remove_native_touch_id_mapping_(false) {
   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);
 
   FixRotationAngle();
   if (type() == ET_TOUCH_RELEASED || type() == ET_TOUCH_CANCELLED)
     should_remove_native_touch_id_mapping_ = true;
 }
 
 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()),
+      unique_touch_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()),
+      unique_touch_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();
 }
 
@@ skipping 396 matching lines @@
                    gfx::PointF(x, y),
                    time_stamp,
                    flags | EF_FROM_TOUCH),
       details_(details) {
 }
 
 GestureEvent::~GestureEvent() {
 }
 
 }  // namespace ui