Make createOptDrawState return NULL if we would end up not drawing

src/gpu/GrOptDrawState.h

Index: src/gpu/GrOptDrawState.h
diff --git a/src/gpu/GrOptDrawState.h b/src/gpu/GrOptDrawState.h
index f0a726e9547d5d7bddffaf145a690ffcd0244432..1f8c442230f864ac58c342a78deeb7863c8cc251 100644
--- a/src/gpu/GrOptDrawState.h
+++ b/src/gpu/GrOptDrawState.h
@@ -8,7 +8,15 @@
 #ifndef GrOptDrawState_DEFINED
 #define GrOptDrawState_DEFINED
 
-#include "GrDrawState.h"
+#include "GrColor.h"
+#include "GrGpu.h"
+#include "GrProcessorStage.h"
+#include "GrStencil.h"
+#include "GrTypesPriv.h"
+#include "SkMatrix.h"
+#include "SkRefCnt.h"
+
+class GrDrawState;
 
 /**
  * Class that holds an optimized version of a GrDrawState. It is meant to be an immutable class,
@@ -16,6 +24,15 @@
  */
 class GrOptDrawState : public SkRefCnt {
 public:
+    /**
+     * Returns a snapshot of the current optimized state. If the current drawState has a valid
+     * cached optimiezed state it will simply return a pointer to it otherwise it will create a new
+     * GrOptDrawState. In all cases the GrOptDrawState is reffed and ownership is given to the
+     * caller.
+     */
+    static GrOptDrawState* Create(const GrDrawState& drawState, const GrDrawTargetCaps& caps,
+                                  GrGpu::DrawType drawType);
+
     bool operator== (const GrOptDrawState& that) const;
 
     ///////////////////////////////////////////////////////////////////////////
@@ -443,7 +460,6 @@ private:
     PrimaryOutputType  fPrimaryOutputType : 8;
     SecondaryOutputType  fSecondaryOutputType : 8;
 
-    friend GrOptDrawState* GrDrawState::createOptState(const GrDrawTargetCaps&) const;
     typedef SkRefCnt INHERITED;
 };