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..9859d2b18d2cd46fd7e696ab1ca0e618af30c6e2 100644
--- a/content/browser/renderer_host/input/motion_event_web.cc
+++ b/content/browser/renderer_host/input/motion_event_web.cc
@@ -12,6 +12,7 @@
 #include "base/logging.h"
 #include "content/browser/renderer_host/input/web_input_event_util.h"
 #include "content/common/input/web_touch_event_traits.h"
+#include "ui/events/base_event_utils.h"
 
 using blink::WebInputEvent;
 using blink::WebTouchEvent;
@@ -63,14 +64,15 @@ int GetActionIndexFrom(const WebTouchEvent& event) {
 MotionEventWeb::MotionEventWeb(const WebTouchEvent& event)
     : event_(event),
       cached_action_(GetActionFrom(event)),
-      cached_action_index_(GetActionIndexFrom(event)) {
+      cached_action_index_(GetActionIndexFrom(event)),
+      unique_event_id_(event.uniqueTouchEventId) {
   DCHECK_GT(GetPointerCount(), 0U);
 }
 
 MotionEventWeb::~MotionEventWeb() {}
 
-int MotionEventWeb::GetId() const {
-  return 0;
+uint64 MotionEventWeb::GetUniqueEventId() const {
+  return unique_event_id_;
 }
 
 MotionEventWeb::Action MotionEventWeb::GetAction() const {