SurfaceFlinger: Add a test to ensure buffer takes priority over blur

Test: atest
LayerTransactionTest#BufferTakesPriorityOverBlur
Bug: 245052266

Change-Id: Ide73878fc55e0b75cc63076cba82f16e6e91446c
diff --git a/services/surfaceflinger/tests/LayerTransaction_test.cpp b/services/surfaceflinger/tests/LayerTransaction_test.cpp
index 513fdc3..c206e1f 100644
--- a/services/surfaceflinger/tests/LayerTransaction_test.cpp
+++ b/services/surfaceflinger/tests/LayerTransaction_test.cpp
@@ -154,6 +154,36 @@
 
     ASSERT_EQ(OK, producer->disconnect(NATIVE_WINDOW_API_CPU));
 }
+
+// b/245052266 - we possible could support blur and a buffer at the same layer but
+// might break existing assumptions at higher level. This test captures the current
+// expectations. A layer drawing a buffer will not support blur.
+TEST_F(LayerTransactionTest, BufferTakesPriorityOverBlur) {
+    sp<SurfaceControl> layer;
+    ASSERT_NO_FATAL_FAILURE(layer = createLayer("test", 32, 32));
+    ASSERT_NO_FATAL_FAILURE(fillBufferStateLayerColor(layer, Color::RED, 32, 32));
+    Transaction().setBackgroundBlurRadius(layer, 5).apply();
+    {
+        SCOPED_TRACE("BufferTakesPriorityOverBlur");
+        const Rect rect(0, 0, 32, 32);
+        auto shot = screenshot();
+        shot->expectColor(rect, Color::RED);
+    }
+}
+
+TEST_F(LayerTransactionTest, BufferTakesPriorityOverColor) {
+    sp<SurfaceControl> layer;
+    ASSERT_NO_FATAL_FAILURE(layer = createLayer("test", 32, 32));
+    ASSERT_NO_FATAL_FAILURE(fillBufferStateLayerColor(layer, Color::RED, 32, 32));
+    Transaction().setColor(layer, {Color::GREEN.r, Color::GREEN.g, Color::GREEN.b}).apply();
+    {
+        SCOPED_TRACE("BufferTakesPriorityOverColor");
+        const Rect rect(0, 0, 32, 32);
+        auto shot = screenshot();
+        shot->expectColor(rect, Color::RED);
+    }
+}
+
 } // namespace android
 
 // TODO(b/129481165): remove the #pragma below and fix conversion issues