allow subpixel positioning w/ bitmap filtering

src/core/SkBitmapProcState.h

Index: src/core/SkBitmapProcState.h
diff --git a/src/core/SkBitmapProcState.h b/src/core/SkBitmapProcState.h
index 663bcb8be91b03722b314cd9c1e0bb5f3900404d..b047d57399f22c1eaee5ade3f88dbe9c4a148334 100644
--- a/src/core/SkBitmapProcState.h
+++ b/src/core/SkBitmapProcState.h
@@ -172,6 +172,8 @@ private:
     // Return false if we failed to setup for fast translate (e.g. overflow)
     bool setupForTranslate();
 
+    bool isInverseTrivial() const;
+
 #ifdef SK_DEBUG
     static void DebugMatrixProc(const SkBitmapProcState&,
                                 uint32_t[], int count, int x, int y);