SF: Delegate ICompositor interfacing to Scheduler

Factor out MessageQueue's calls to commit/composite/sample into an
onFrameSignal delegate that Scheduler implements, since the policy
for ICompositor interfacing (e.g. whether to composite displays
sequentially or concurrently) will be the latter's responsibility.

Improve type correctness by replacing more nsecs_t with TimePoint/
Duration, and int64_t with a new VsyncId type.

Bug: 241285191
Test: Boot
Change-Id: I5039894038b62a562c1f93b7cea41751f7f76ca6
diff --git a/services/surfaceflinger/tests/unittests/TestableScheduler.h b/services/surfaceflinger/tests/unittests/TestableScheduler.h
index 4708572..66cdfd7 100644
--- a/services/surfaceflinger/tests/unittests/TestableScheduler.h
+++ b/services/surfaceflinger/tests/unittests/TestableScheduler.h
@@ -109,8 +109,8 @@
 
 private:
     // ICompositor overrides:
-    bool commit(nsecs_t, int64_t, nsecs_t) override { return false; }
-    void composite(nsecs_t, int64_t) override {}
+    bool commit(TimePoint, VsyncId, TimePoint) override { return false; }
+    void composite(TimePoint, VsyncId) override {}
     void sample() override {}
 };