Remove redundant vlayout masks and wasted vlayout bits

Review URL: http://codereview.appspot.com/6345080/


git-svn-id: http://skia.googlecode.com/svn/trunk@4506 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrDrawTarget.h b/src/gpu/GrDrawTarget.h
index 66256cf..3f1ad59 100644
--- a/src/gpu/GrDrawTarget.h
+++ b/src/gpu/GrDrawTarget.h
@@ -192,11 +192,9 @@
     static bool StageUsesTexCoords(GrVertexLayout layout, int stage);
 
 private:
-    static const int TEX_COORD_BIT_CNT = GrDrawState::kNumStages *
-                                         GrDrawState::kMaxTexCoords;
-    static const int STAGE_BIT_CNT = TEX_COORD_BIT_CNT +
-        GrDrawState::kNumStages;
-
+    // non-stage bits start at this index.
+    static const int STAGE_BIT_CNT = GrDrawState::kNumStages *
+                                     GrDrawState::kMaxTexCoords;
 public:
 
     /**