Front buffered layers vote for max

...because all known use-cases for beam racing want low latency which
implies clocking the display to max

Bug: 305997105
Test: libsurfaceflinger_unittest
Test: test app with front buffered layers + youtube pip stays at max
Change-Id: Ibe33d4b43ea4943874f104409e3bc247f00cae33
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 700baa2..98f34cf 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -4230,6 +4230,14 @@
     return hasBufferOrSidebandStream() ? mBufferInfo.mDataspace : mDrawingState.dataspace;
 }
 
+bool Layer::isFrontBuffered() const {
+    if (mBufferInfo.mBuffer == nullptr) {
+        return false;
+    }
+
+    return mBufferInfo.mBuffer->getUsage() & AHARDWAREBUFFER_USAGE_FRONT_BUFFER;
+}
+
 ui::Dataspace Layer::translateDataspace(ui::Dataspace dataspace) {
     ui::Dataspace updatedDataspace = dataspace;
     // translate legacy dataspaces to modern dataspaces