Let InputFlinger generate event IDs.

Also send event IDs via InputMessage and add some atrace calls to form a
complete chain of input event processing.

Bug: 144889238
Test: systrace shows correct event IDs.
Test: atest inputflinger_tests
Change-Id: I3c561b03b0ba75c22115ae020e6b41855686ab64
Merged-In: I3c561b03b0ba75c22115ae020e6b41855686ab64
(cherry picked from commit ff1f1bb99489fd372c57908dafdd3817a33db0c5)
diff --git a/services/inputflinger/dispatcher/InputDispatcher.h b/services/inputflinger/dispatcher/InputDispatcher.h
index 482133e..4aa47f8 100644
--- a/services/inputflinger/dispatcher/InputDispatcher.h
+++ b/services/inputflinger/dispatcher/InputDispatcher.h
@@ -156,6 +156,8 @@
 
     DropReason mLastDropReason GUARDED_BY(mLock);
 
+    const IdGenerator mIdGenerator;
+
     // With each iteration, InputDispatcher nominally processes one queued event,
     // a timeout, or a response from an input consumer.
     // This method should only be called on the input dispatcher's own thread.