Set the unique_event_id when converting from TouchEvent to WebTouchEvent

content/browser/renderer_host/input/motion_event_android.cc

Index: content/browser/renderer_host/input/motion_event_android.cc
diff --git a/content/browser/renderer_host/input/motion_event_android.cc b/content/browser/renderer_host/input/motion_event_android.cc
index 3f18f95561b3d650ccc3b3d36bd040f6f12f587f..25d3b09a799bd92e9a8471b3c380c5eeefc89e9a 100644
--- a/content/browser/renderer_host/input/motion_event_android.cc
+++ b/content/browser/renderer_host/input/motion_event_android.cc
@@ -115,6 +115,16 @@ size_t ToValidHistorySize(jint history_size, ui::MotionEvent::Action action) {
   return history_size;
 }
 
+uint64 get_next_event_id() {
+  // Set the first unique_id_ to 1 because we set id to 0 for other types
+  // of events.
+  static uint64 id = 1;
+  if (id==0)
+    id++;
+  DCHECK_NE(id, 0UL);
+  return id++;
+}
+
 }  // namespace
 
 MotionEventAndroid::Pointer::Pointer(jint id,
@@ -164,7 +174,8 @@ MotionEventAndroid::MotionEventAndroid(float pix_to_dip,
       cached_button_state_(FromAndroidButtonState(android_button_state)),
       cached_flags_(FromAndroidMetaState(meta_state)),
       cached_raw_position_offset_(ToDips(raw_offset_x_pixels),
-                                  ToDips(raw_offset_y_pixels)) {
+                                  ToDips(raw_offset_y_pixels)),
+      unique_id_(get_next_event_id()) {
   DCHECK_GT(pointer_count, 0);
 
   event_.Reset(env, event);
@@ -182,6 +193,10 @@ int MotionEventAndroid::GetId() const {
   return 0;
 }
 
+uint64 MotionEventAndroid::GetUniqueId() const {
+  return unique_id_;
+}
+
 MotionEventAndroid::Action MotionEventAndroid::GetAction() const {
   return cached_action_;
 }