Make pinch zoom work on chromeos by setting touch id correctly

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"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 
@@ skipping 744 matching lines @@
       f &= ~EF_IS_TRIPLE_CLICK;
       break;
     case 3:
       f &= ~EF_IS_DOUBLE_CLICK;
       f |= EF_IS_TRIPLE_CLICK;
       break;
   }
   set_flags(f);
 }
 
+void MouseEvent::set_pointer_details(const PointerDetails& details) {
+  if (details.pointer_type == EventPointerType::POINTER_TYPE_TOUCH) {

[sadrul, 2017/03/01 15:35:59]

For MouseEvent, when do we set pointer_type to TYPE_TOUCH?

[lanwei, 2017/03/01 20:12:22]

So far, I have not seen. I am afraid it may be set from a touch type in the
future.

+    DCHECK(pointer_details_.id == 0 || details.id != 0);
+  } else {
+    DCHECK(pointer_details_.id == PointerEvent::kMousePointerId ||
+           details.id != PointerEvent::kMousePointerId);
+  }
+  pointer_details_ = details;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // MouseWheelEvent
 
 MouseWheelEvent::MouseWheelEvent(const base::NativeEvent& native_event)
     : MouseEvent(native_event),
       offset_(GetMouseWheelOffset(native_event)) {
 }
 
 MouseWheelEvent::MouseWheelEvent(const ScrollEvent& scroll_event)
     : MouseEvent(scroll_event),
@@ skipping 190 matching lines @@
       static_cast<EventResult>(result() | ER_DISABLE_SYNC_HANDLING));
 }
 
 void TouchEvent::FixRotationAngle() {
   while (rotation_angle_ < 0)
     rotation_angle_ += 180;
   while (rotation_angle_ >= 180)
     rotation_angle_ -= 180;
 }
 
+void TouchEvent::set_pointer_details(const PointerDetails& pointer_details) {
+  if (pointer_details.pointer_type == EventPointerType::POINTER_TYPE_TOUCH) {
+    DCHECK(pointer_details_.id == 0 || pointer_details.id != 0);
+  } else {
+    DCHECK(pointer_details_.id == PointerEvent::kMousePointerId ||
+           pointer_details.id != PointerEvent::kMousePointerId);

[sadrul, 2017/03/01 15:35:59]

When do we create a TouchEvent when pointer_type is not TYPE_TOUCH?

[lanwei, 2017/03/01 20:12:22]

On Kevin (chromebook) device, the pointer type is pen, but it is sent as a touch
event.

+  }
+  pointer_details_ = pointer_details;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // PointerEvent
 
 bool PointerEvent::CanConvertFrom(const Event& event) {
   switch (event.type()) {
     case ET_MOUSE_PRESSED:
     case ET_MOUSE_DRAGGED:
     case ET_MOUSE_MOVED:
     case ET_MOUSE_ENTERED:
     case ET_MOUSE_EXITED:
@@ skipping 466 matching lines @@
                    flags | EF_FROM_TOUCH),
       details_(details),
       unique_touch_event_id_(unique_touch_event_id) {
   latency()->set_source_event_type(ui::SourceEventType::TOUCH);
 }
 
 GestureEvent::~GestureEvent() {
 }
 
 }  // namespace ui