Touch emulator: allow multiple touch streams.

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index c0196dee6140393cb403eaa4d5a7b024e484e1c2..f378a26e4c57ce18ce58914b42f9f38973ceeb98 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -964,22 +964,41 @@ void RenderWidgetHostImpl::ForwardGestureEventWithLatencyInfo(
   input_router_->SendGestureEvent(gesture_with_latency);
 }
 
-void RenderWidgetHostImpl::ForwardTouchEvent(
+void RenderWidgetHostImpl::ForwardEmulatedTouchEvent(
       const blink::WebTouchEvent& touch_event) {
-  ForwardTouchEventWithLatencyInfo(touch_event, ui::LatencyInfo());
+  ForwardTouchEventWithLatencyInfoFromStream(
+      touch_event, ui::LatencyInfo(), TouchStreamTracker::EMULATED_STREAM);
 }
 
 void RenderWidgetHostImpl::ForwardTouchEventWithLatencyInfo(
       const blink::WebTouchEvent& touch_event,
       const ui::LatencyInfo& ui_latency) {
+  ForwardTouchEventWithLatencyInfoFromStream(
+      touch_event, ui_latency, TouchStreamTracker::NATIVE_STREAM);
+}
+
+void RenderWidgetHostImpl::ForwardTouchEventWithLatencyInfoFromStream(
+    const blink::WebTouchEvent& touch_event,
+    const ui::LatencyInfo& ui_latency,
+    TouchStreamTracker::TouchStream stream) {
   TRACE_EVENT0("input", "RenderWidgetHostImpl::ForwardTouchEvent");
 
-  // Always forward TouchEvents for touch stream consistency. They will be
-  // ignored if appropriate in FilterInputEvent().
+  // Always forward TouchEvents from active touch stream for consistency.
+  // They will be ignored if appropriate in FilterInputEvent().
 
   ui::LatencyInfo latency_info =
       CreateRWHLatencyInfoIfNotExist(&ui_latency, touch_event.type);
   TouchEventWithLatencyInfo touch_with_latency(touch_event, latency_info);
+
+  if (touch_stream_tracker_) {
+    InputEventAckState ack_result =
+        touch_stream_tracker_->FilterTouchEventFromStream(touch_event, stream);
+    if (ack_result != INPUT_EVENT_ACK_STATE_UNKNOWN) {
+      OnTouchEventAckFromStream(touch_with_latency, ack_result, stream);
+      return;
+    }
+  }
+
   input_router_->SendTouchEvent(touch_with_latency);
 }
 
@@ -1629,8 +1648,10 @@ void RenderWidgetHostImpl::OnSetTouchEventEmulationEnabled(
     delegate_->OnTouchEmulationEnabled(enabled);
 
   if (enabled) {
-    if (!touch_emulator_)
+    if (!touch_emulator_) {
+      touch_stream_tracker_.reset(new TouchStreamTracker());
       touch_emulator_.reset(new TouchEmulator(this));
+    }
     touch_emulator_->Enable(allow_pinch);
   } else {
     if (touch_emulator_)
@@ -1891,6 +1912,16 @@ void RenderWidgetHostImpl::OnGestureEventAck(
 void RenderWidgetHostImpl::OnTouchEventAck(
     const TouchEventWithLatencyInfo& event,
     InputEventAckState ack_result) {
+  TouchStreamTracker::TouchStream stream = TouchStreamTracker::NATIVE_STREAM;
+  if (touch_stream_tracker_)
+    stream = touch_stream_tracker_->OnTouchEventAck(event, ack_result);
+  OnTouchEventAckFromStream(event, ack_result, stream);
+}
+
+void RenderWidgetHostImpl::OnTouchEventAckFromStream(
+    const TouchEventWithLatencyInfo& event,
+    InputEventAckState ack_result,
+    TouchStreamTracker::TouchStream stream) {
   TouchEventWithLatencyInfo touch_event = event;
   touch_event.latency.AddLatencyNumber(
       ui::INPUT_EVENT_LATENCY_ACKED_TOUCH_COMPONENT, 0, 0);
@@ -1902,9 +1933,13 @@ void RenderWidgetHostImpl::OnTouchEventAck(
   }
   ComputeTouchLatency(touch_event.latency);
 
-  if (touch_emulator_ && touch_emulator_->HandleTouchEventAck(ack_result))
+  if (stream == TouchStreamTracker::EMULATED_STREAM) {
+    DCHECK(touch_emulator_);
+    touch_emulator_->HandleTouchEventAck(ack_result);
     return;
+  }
 
+  DCHECK(stream == TouchStreamTracker::NATIVE_STREAM);
   if (view_)
     view_->ProcessAckedTouchEvent(touch_event, ack_result);
 }