Set the unique_event_id when converting from TouchEvent to WebTouchEvent

content/browser/renderer_host/input/motion_event_web.cc

Index: content/browser/renderer_host/input/motion_event_web.cc
diff --git a/content/browser/renderer_host/input/motion_event_web.cc b/content/browser/renderer_host/input/motion_event_web.cc
index 2d276f0371ea23757ad508f23df1cdb496d015ed..7300e816cb77c94d7ddab870592bbbbf4d1383a4 100644
--- a/content/browser/renderer_host/input/motion_event_web.cc
+++ b/content/browser/renderer_host/input/motion_event_web.cc
@@ -73,6 +73,10 @@ int MotionEventWeb::GetId() const {
   return 0;
 }
 
+uint32 MotionEventWeb::GetUniqueId() const {
+  return 0;
+}
+
 MotionEventWeb::Action MotionEventWeb::GetAction() const {
   return cached_action_;
 }