Refactor blending and texture gl state

Change-Id: Ia6b3c8b2afd3dfcee7f3ce401d846b789612054a
diff --git a/libs/hwui/Dither.h b/libs/hwui/Dither.h
index 092ebf2..38633af 100644
--- a/libs/hwui/Dither.h
+++ b/libs/hwui/Dither.h
@@ -36,7 +36,7 @@
  */
 class Dither {
 public:
-    Dither();
+    Dither(Caches& caches);
 
     void clear();
     void setupProgram(Program* program, GLuint* textureUnit);
@@ -44,7 +44,7 @@
 private:
     void bindDitherTexture();
 
-    Caches* mCaches;
+    Caches& mCaches;
     bool mInitialized;
     GLuint mDitherTexture;
 };