InputDispatcher: Add InputTracerInterface for tracing input events

The interface documents how the tracer will interact with
InputDispatcher.

Bug: 210460522
Test: Build
Change-Id: Id97f9b0851f1248956b95e8b18b2302ecff1bff5
diff --git a/services/inputflinger/dispatcher/Entry.h b/services/inputflinger/dispatcher/Entry.h
index e2e13c3..a915805 100644
--- a/services/inputflinger/dispatcher/Entry.h
+++ b/services/inputflinger/dispatcher/Entry.h
@@ -18,6 +18,7 @@
 
 #include "InjectionState.h"
 #include "InputTarget.h"
+#include "trace/EventTrackerInterface.h"
 
 #include <gui/InputApplication.h>
 #include <input/Input.h>
@@ -125,6 +126,7 @@
     int32_t scanCode;
     int32_t metaState;
     nsecs_t downTime;
+    std::unique_ptr<trace::EventTrackerInterface> traceTracker;
 
     bool syntheticRepeat; // set to true for synthetic key repeats
 
@@ -147,6 +149,8 @@
     std::string getDescription() const override;
 };
 
+std::ostream& operator<<(std::ostream& out, const KeyEntry& motionEntry);
+
 struct MotionEntry : EventEntry {
     int32_t deviceId;
     uint32_t source;
@@ -165,6 +169,7 @@
     nsecs_t downTime;
     std::vector<PointerProperties> pointerProperties;
     std::vector<PointerCoords> pointerCoords;
+    std::unique_ptr<trace::EventTrackerInterface> traceTracker;
 
     size_t getPointerCount() const { return pointerProperties.size(); }