Add latency info to input events sent to RenderWidget.

content/browser/renderer_host/gesture_event_filter.cc

Index: content/browser/renderer_host/gesture_event_filter.cc
diff --git a/content/browser/renderer_host/gesture_event_filter.cc b/content/browser/renderer_host/gesture_event_filter.cc
index 02ed0c31cfdceae33470d2c4be1a953caeaee534..8c09451763c8f52d572a14b5b88cb6913c970e72 100644
--- a/content/browser/renderer_host/gesture_event_filter.cc
+++ b/content/browser/renderer_host/gesture_event_filter.cc
@@ -75,7 +75,7 @@ GestureEventFilter::GestureEventFilter(RenderWidgetHostImpl* rwhv)
 GestureEventFilter::~GestureEventFilter() { }
 
 bool GestureEventFilter::ShouldDiscardFlingCancelEvent(
-    const WebKit::WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   if (coalesced_gesture_events_.empty() && fling_in_progress_)
     return false;
   GestureEventQueue::reverse_iterator it =
@@ -91,7 +91,7 @@ bool GestureEventFilter::ShouldDiscardFlingCancelEvent(
 }
 
 bool GestureEventFilter::ShouldForwardForBounceReduction(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   if (debounce_interval_time_ms_ ==  0)
     return true;
   switch (gesture_event.type) {
@@ -127,7 +127,8 @@ bool GestureEventFilter::ShouldForwardForBounceReduction(
 }
 
 // NOTE: The filters are applied successively. This simplifies the change.
-bool GestureEventFilter::ShouldForward(const WebGestureEvent& gesture_event) {
+bool GestureEventFilter::ShouldForward(
+    const GestureEventLatency& gesture_event) {
   return ShouldForwardForZeroVelocityFlingStart(gesture_event) &&
       ShouldForwardForBounceReduction(gesture_event) &&
       ShouldForwardForGFCFiltering(gesture_event) &&
@@ -137,7 +138,7 @@ bool GestureEventFilter::ShouldForward(const WebGestureEvent& gesture_event) {
 }
 
 bool GestureEventFilter::ShouldForwardForZeroVelocityFlingStart(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   return gesture_event.type != WebInputEvent::GestureFlingStart ||
       gesture_event.sourceDevice != WebGestureEvent::Touchpad ||
       gesture_event.data.flingStart.velocityX != 0 ||
@@ -145,13 +146,13 @@ bool GestureEventFilter::ShouldForwardForZeroVelocityFlingStart(
 }
 
 bool GestureEventFilter::ShouldForwardForGFCFiltering(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   return gesture_event.type != WebInputEvent::GestureFlingCancel ||
       !ShouldDiscardFlingCancelEvent(gesture_event);
 }
 
 bool GestureEventFilter::ShouldForwardForTapSuppression(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   switch (gesture_event.type) {
     case WebInputEvent::GestureFlingCancel:
       if (gesture_event.sourceDevice == WebGestureEvent::Touchscreen)
@@ -176,7 +177,7 @@ bool GestureEventFilter::ShouldForwardForTapSuppression(
 }
 
 bool GestureEventFilter::ShouldForwardForTapDeferral(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   switch (gesture_event.type) {
     case WebInputEvent::GestureTapDown:
       // GestureTapDown is always paired with either a Tap, or TapCancel, so it
@@ -221,7 +222,7 @@ bool GestureEventFilter::ShouldForwardForTapDeferral(
 }
 
 bool GestureEventFilter::ShouldForwardForCoalescing(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   switch (gesture_event.type) {
     case WebInputEvent::GestureFlingCancel:
       fling_in_progress_ = false;
@@ -270,13 +271,13 @@ void GestureEventFilter::ProcessGestureAck(bool processed, int type) {
   if (ignore_next_ack_) {
     ignore_next_ack_ = false;
   } else if (!coalesced_gesture_events_.empty()) {
-    const WebGestureEvent& next_gesture_event =
+    const GestureEventLatency& next_gesture_event =
         coalesced_gesture_events_.front();
     render_widget_host_->ForwardGestureEventImmediately(next_gesture_event);
     // TODO(yusufo): Introduce GesturePanScroll so that these can be combined
     // into one gesture and kept inside the queue that way.
     if (coalesced_gesture_events_.size() > 1) {
-      const WebGestureEvent& second_gesture_event =
+      const GestureEventLatency& second_gesture_event =
           coalesced_gesture_events_[1];
       if (next_gesture_event.type == WebInputEvent::GestureScrollUpdate &&
           second_gesture_event.type == WebInputEvent::GesturePinchUpdate) {
@@ -316,13 +317,13 @@ bool GestureEventFilter::ShouldHandleEventNow() {
 }
 
 void GestureEventFilter::ForwardGestureEventForDeferral(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   if (ShouldForwardForTapDeferral(gesture_event))
     ForwardGestureEventSkipDeferral(gesture_event);
 }
 
 void GestureEventFilter::ForwardGestureEventSkipDeferral(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   if (ShouldForwardForCoalescing(gesture_event))
       render_widget_host_->ForwardGestureEventImmediately(gesture_event);
 }
@@ -352,12 +353,12 @@ void GestureEventFilter::SendScrollEndingEventsNow() {
 }
 
 void GestureEventFilter::MergeOrInsertScrollAndPinchEvent(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   if (coalesced_gesture_events_.size() <= 1) {
     coalesced_gesture_events_.push_back(gesture_event);
     return;
   }
-  WebGestureEvent* last_event = &coalesced_gesture_events_.back();
+  GestureEventLatency* last_event = &coalesced_gesture_events_.back();
   if (gesture_event.type == WebInputEvent::GestureScrollUpdate &&
       last_event->type == WebInputEvent::GestureScrollUpdate &&
       last_event->modifiers == gesture_event.modifiers) {
@@ -365,6 +366,7 @@ void GestureEventFilter::MergeOrInsertScrollAndPinchEvent(
         gesture_event.data.scrollUpdate.deltaX;
     last_event->data.scrollUpdate.deltaY +=
         gesture_event.data.scrollUpdate.deltaY;
+    last_event->latency_info.MergeWith(gesture_event.latency_info);
     return;
   }
   if (coalesced_gesture_events_.size() == 2 ||
@@ -373,10 +375,12 @@ void GestureEventFilter::MergeOrInsertScrollAndPinchEvent(
     coalesced_gesture_events_.push_back(gesture_event);
     return;
   }
-  WebGestureEvent scroll_event;
-  WebGestureEvent pinch_event;
+  GestureEventLatency scroll_event;
+  GestureEventLatency pinch_event;
   scroll_event.modifiers |= gesture_event.modifiers;
   scroll_event.timeStampSeconds = gesture_event.timeStampSeconds;
+  scroll_event.latency_info = gesture_event.latency_info;
+  scroll_event.latency_info.MergeWith(last_event->latency_info);
   pinch_event = scroll_event;
   scroll_event.type = WebInputEvent::GestureScrollUpdate;
   pinch_event.type = WebInputEvent::GesturePinchUpdate;
@@ -386,9 +390,11 @@ void GestureEventFilter::MergeOrInsertScrollAndPinchEvent(
       gesture_event.y : last_event->y;
 
   combined_scroll_pinch_.ConcatTransform(GetTransformForEvent(gesture_event));
-  WebGestureEvent* second_last_event = &coalesced_gesture_events_
+  GestureEventLatency* second_last_event = &coalesced_gesture_events_
       [coalesced_gesture_events_.size() - 2];
   if (ShouldTryMerging(gesture_event, *second_last_event)) {
+    scroll_event.latency_info.MergeWith(second_last_event->latency_info);
+    pinch_event.latency_info.MergeWith(second_last_event->latency_info);
     coalesced_gesture_events_.pop_back();
   } else {
     DCHECK(combined_scroll_pinch_ == GetTransformForEvent(gesture_event));
@@ -408,8 +414,8 @@ void GestureEventFilter::MergeOrInsertScrollAndPinchEvent(
   coalesced_gesture_events_.push_back(pinch_event);
 }
 
-bool GestureEventFilter::ShouldTryMerging(const WebGestureEvent& new_event,
-    const WebGestureEvent& event_in_queue) {
+bool GestureEventFilter::ShouldTryMerging(const GestureEventLatency& new_event,
+    const GestureEventLatency& event_in_queue) {
   DLOG_IF(WARNING,
           new_event.timeStampSeconds <
           event_in_queue.timeStampSeconds)
@@ -420,7 +426,7 @@ bool GestureEventFilter::ShouldTryMerging(const WebGestureEvent& new_event,
 }
 
 gfx::Transform GestureEventFilter::GetTransformForEvent(
-    const WebGestureEvent& gesture_event) {
+    const GestureEventLatency& gesture_event) {
   gfx::Transform gesture_transform = gfx::Transform();
   if (gesture_event.type == WebInputEvent::GestureScrollUpdate) {
     gesture_transform.Translate(gesture_event.data.scrollUpdate.deltaX,