Track plugin input event latency

ppapi/tests/test_input_event.cc

Index: ppapi/tests/test_input_event.cc
diff --git a/ppapi/tests/test_input_event.cc b/ppapi/tests/test_input_event.cc
index 4fd0edab0e12af506562bfadd7c5f3807a410d5a..902d345ad1c3c5f4275aee482747d8d3887b8e45 100644
--- a/ppapi/tests/test_input_event.cc
+++ b/ppapi/tests/test_input_event.cc
@@ -31,6 +31,7 @@ pp::Point GetCenter(const pp::Rect& rect) {
 
 void TestInputEvent::RunTests(const std::string& filter) {
   RUN_TEST(Events, filter);
+  RUN_TEST(EventsLatencyTracking, filter);
 
   // The AcceptTouchEvent_N tests should not be run when the filter is empty;
   // they can only be run one at a time.
@@ -55,7 +56,9 @@ TestInputEvent::TestInputEvent(TestingInstance* instance)
       view_rect_(),
       expected_input_event_(0),
       received_expected_event_(false),
-      received_finish_message_(false) {
+      received_finish_message_(false),
+      enable_latency_tracking_(false),
+      last_latency_tracking_successful_(false) {
 }
 
 TestInputEvent::~TestInputEvent() {
@@ -72,6 +75,8 @@ TestInputEvent::~TestInputEvent() {
 bool TestInputEvent::Init() {
   input_event_interface_ = static_cast<const PPB_InputEvent*>(
       pp::Module::Get()->GetBrowserInterface(PPB_INPUT_EVENT_INTERFACE));
+  input_event_private_interface_ = static_cast<const PPB_InputEvent_Private*>(
+      pp::Module::Get()->GetBrowserInterface(PPB_INPUTEVENT_PRIVATE_INTERFACE));
   mouse_input_event_interface_ = static_cast<const PPB_MouseInputEvent*>(
       pp::Module::Get()->GetBrowserInterface(
           PPB_MOUSE_INPUT_EVENT_INTERFACE));
@@ -87,6 +92,7 @@ bool TestInputEvent::Init() {
 
   bool success =
       input_event_interface_ &&
+      input_event_private_interface_ &&
       mouse_input_event_interface_ &&
       wheel_input_event_interface_ &&
       keyboard_input_event_interface_ &&
@@ -305,6 +311,10 @@ bool TestInputEvent::HandleInputEvent(const pp::InputEvent& input_event) {
         expected_input_event_.pp_resource());
   }
   // Handle all input events.
+  if (enable_latency_tracking_) {
+    pp::InputEventPrivate private_event(input_event);
+    last_latency_tracking_successful_ = private_event.TraceInputLatency(true);
+  }
   return true;
 }
 
@@ -321,6 +331,28 @@ void TestInputEvent::DidChangeView(const pp::View& view) {
   view_rect_ = view.GetRect();
 }
 
+std::string TestInputEvent::TestEventsLatencyTracking() {
+  enable_latency_tracking_ = true;
+  input_event_interface_->RequestInputEvents(instance_->pp_instance(),
+                                             PP_INPUTEVENT_CLASS_TOUCH);
+  PostMessageBarrier();
+
+  ASSERT_TRUE(SimulateInputEvent(CreateTouchEvent(PP_INPUTEVENT_TYPE_TOUCHSTART,
+                                                  pp::FloatPoint(12, 23))));
+  // Without calling StartTrackingLatency() first, TraceInputLatency() won't
+  // take effect and will return false;
+  ASSERT_FALSE(last_latency_tracking_successful_);
+
+  input_event_private_interface_->StartTrackingLatency(
+      instance_->pp_instance());
+
+  ASSERT_TRUE(SimulateInputEvent(CreateTouchEvent(PP_INPUTEVENT_TYPE_TOUCHSTART,
+                                                  pp::FloatPoint(12, 23))));
+  ASSERT_TRUE(last_latency_tracking_successful_);
+
+  PASS();
+}
+
 std::string TestInputEvent::TestEvents() {
   // Request all input event classes.
   input_event_interface_->RequestInputEvents(instance_->pp_instance(),