Add test for first draw blend behavior in HWUI pipeline

Bug: 65077146
Test: BakedOpRendererTests
Change-Id: Ia3139a01fe25344a19f2b947069bd686303b9fd5
diff --git a/libs/hwui/renderstate/Blend.h b/libs/hwui/renderstate/Blend.h
index ec0e114..a9de246 100644
--- a/libs/hwui/renderstate/Blend.h
+++ b/libs/hwui/renderstate/Blend.h
@@ -40,6 +40,14 @@
             GLenum* outSrc, GLenum* outDst);
     void setFactors(GLenum src, GLenum dst);
 
+    bool  getEnabled() {
+        return mEnabled;
+    }
+    void getFactors(GLenum* src, GLenum* dst) {
+        *src = mSrcMode;
+        *dst = mDstMode;
+    }
+
     void dump();
 private:
     Blend();