Report LatencyInfo through trace buffer

content/browser/renderer_host/input/touch_event_queue.cc

Index: content/browser/renderer_host/input/touch_event_queue.cc
diff --git a/content/browser/renderer_host/input/touch_event_queue.cc b/content/browser/renderer_host/input/touch_event_queue.cc
index 9d0394ef162d034a0f43ebe90cb34969011867de..f5f0a478f538666e559ffcb98f603e448b264648 100644
--- a/content/browser/renderer_host/input/touch_event_queue.cc
+++ b/content/browser/renderer_host/input/touch_event_queue.cc
@@ -69,11 +69,11 @@ class CoalescedWebTouchEvent {
     return coalesced_event_;
   }
 
-  WebTouchEventWithLatencyList::const_iterator begin() const {
+  WebTouchEventWithLatencyList::iterator begin() {
     return events_.begin();
   }
 
-  WebTouchEventWithLatencyList::const_iterator end() const {
+  WebTouchEventWithLatencyList::iterator end() {
     return events_.end();
   }
 
@@ -123,7 +123,7 @@ void TouchEventQueue::QueueEvent(const TouchEventWithLatencyInfo& event) {
 }
 
 void TouchEventQueue::ProcessTouchAck(InputEventAckState ack_result,
-                                      const ui::LatencyInfo& latency_info) {
+                                      ui::LatencyInfo* latency_info) {

[jdduke (slow), 2013/10/04 02:22:19]

It looks like you can keep this a const ref, same with the
PopTouchEventToClient() arg.

[Yufeng Shen (Slow to review), 2013/10/04 18:03:03]

Done.

   DCHECK(!dispatching_touch_ack_);
   if (touch_queue_.empty())
     return;
@@ -162,16 +162,18 @@ void TouchEventQueue::TryForwardNextEventToRenderer() {
       client_->SendTouchEventImmediately(touch);
       break;
     }
+    ui::LatencyInfo latency;
     PopTouchEventToClient(INPUT_EVENT_ACK_STATE_NO_CONSUMER_EXISTS,
-                          ui::LatencyInfo());
+                          &latency);
   }
 }
 
 void TouchEventQueue::FlushQueue() {
   DCHECK(!dispatching_touch_ack_);
+  ui::LatencyInfo latency;
   while (!touch_queue_.empty())
     PopTouchEventToClient(INPUT_EVENT_ACK_STATE_NOT_CONSUMED,
-                          ui::LatencyInfo());
+                          &latency);
 }
 
 size_t TouchEventQueue::GetQueueSize() const {
@@ -184,7 +186,7 @@ const TouchEventWithLatencyInfo& TouchEventQueue::GetLatestEvent() const {
 
 void TouchEventQueue::PopTouchEventToClient(
     InputEventAckState ack_result,
-    const ui::LatencyInfo& renderer_latency_info) {
+    ui::LatencyInfo* renderer_latency_info) {
   if (touch_queue_.empty())

[jdduke (slow), 2013/10/04 02:22:19]

You're adding renderer_latency_info to latency below, so I think you can keep it
const ref.

[Yufeng Shen (Slow to review), 2013/10/04 18:03:03]

Done.

     return;
   scoped_ptr<CoalescedWebTouchEvent> acked_event(touch_queue_.front());
@@ -194,15 +196,12 @@ void TouchEventQueue::PopTouchEventToClient(
   // to the renderer, or touch-events being queued.
   base::AutoReset<bool> dispatching_touch_ack(&dispatching_touch_ack_, true);
 
-  base::TimeTicks now = base::TimeTicks::HighResNow();
-  for (WebTouchEventWithLatencyList::const_iterator iter = acked_event->begin(),
+  for (WebTouchEventWithLatencyList::iterator iter = acked_event->begin(),
        end = acked_event->end();
        iter != end; ++iter) {
-    ui::LatencyInfo* latency = const_cast<ui::LatencyInfo*>(&(iter->latency));
-    latency->AddNewLatencyFrom(renderer_latency_info);
-    latency->AddLatencyNumberWithTimestamp(
-        ui::INPUT_EVENT_LATENCY_ACKED_COMPONENT, 0, 0, now, 1);
-    client_->OnTouchEventAck((*iter), ack_result);
+    ui::LatencyInfo* latency = &(iter->latency);
+    latency->AddNewLatencyFrom(*renderer_latency_info);
+    client_->OnTouchEventAck(iter->event, ack_result, latency);
   }
 }