SF: add traces for latch unsignled

Add more debug information to traces to determine SF would
not try to latch an unsignaled buffer.

Test: manual
Bug: 285901173
Change-Id: I60a19fe889ce7c052ea4f3fc8f10771494d330aa
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index c52c912..e2e89ad 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4444,26 +4444,27 @@
 bool SurfaceFlinger::shouldLatchUnsignaled(const sp<Layer>& layer, const layer_state_t& state,
                                            size_t numStates, bool firstTransaction) const {
     if (enableLatchUnsignaledConfig == LatchUnsignaledConfig::Disabled) {
-        ALOGV("%s: false (LatchUnsignaledConfig::Disabled)", __func__);
+        ATRACE_FORMAT_INSTANT("%s: false (LatchUnsignaledConfig::Disabled)", __func__);
         return false;
     }
 
     if (enableLatchUnsignaledConfig == LatchUnsignaledConfig::Always) {
-        ALOGV("%s: true (LatchUnsignaledConfig::Always)", __func__);
+        ATRACE_FORMAT_INSTANT("%s: true (LatchUnsignaledConfig::Always)", __func__);
         return true;
     }
 
     // We only want to latch unsignaled when a single layer is updated in this
     // transaction (i.e. not a blast sync transaction).
     if (numStates != 1) {
-        ALOGV("%s: false (numStates=%zu)", __func__, numStates);
+        ATRACE_FORMAT_INSTANT("%s: false (numStates=%zu)", __func__, numStates);
         return false;
     }
 
     if (enableLatchUnsignaledConfig == LatchUnsignaledConfig::AutoSingleLayer) {
         if (!firstTransaction) {
-            ALOGV("%s: false (LatchUnsignaledConfig::AutoSingleLayer; not first transaction)",
-                  __func__);
+            ATRACE_FORMAT_INSTANT("%s: false (LatchUnsignaledConfig::AutoSingleLayer; not first "
+                                  "transaction)",
+                                  __func__);
             return false;
         }
 
@@ -4471,19 +4472,14 @@
         // as it leads to jank due to RenderEngine waiting for unsignaled buffer
         // or window animations being slow.
         if (mScheduler->vsyncModulator().isVsyncConfigEarly()) {
-            ALOGV("%s: false (LatchUnsignaledConfig::AutoSingleLayer; isVsyncConfigEarly)",
-                  __func__);
+            ATRACE_FORMAT_INSTANT("%s: false (LatchUnsignaledConfig::AutoSingleLayer; "
+                                  "isVsyncConfigEarly)",
+                                  __func__);
             return false;
         }
     }
 
-    if (!layer->simpleBufferUpdate(state)) {
-        ALOGV("%s: false (!simpleBufferUpdate)", __func__);
-        return false;
-    }
-
-    ALOGV("%s: true", __func__);
-    return true;
+    return layer->isSimpleBufferUpdate(state);
 }
 
 status_t SurfaceFlinger::setTransactionState(