start to remove lockPixels from bitmapshader

BUG=
R=scroggo@google.com

Review URL: https://codereview.chromium.org/23591030

git-svn-id: http://skia.googlecode.com/svn/trunk@11258 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkBitmapProcState.h b/src/core/SkBitmapProcState.h
index 2522a69..d5a354e 100644
--- a/src/core/SkBitmapProcState.h
+++ b/src/core/SkBitmapProcState.h
@@ -13,6 +13,7 @@
 #include "SkBitmap.h"
 #include "SkBitmapFilter.h"
 #include "SkMatrix.h"
+#include "SkPaint.h"
 #include "SkScaledImageCache.h"
 
 #define FractionalInt_IS_64BIT
@@ -160,7 +161,13 @@
     bool chooseProcs(const SkMatrix& inv, const SkPaint&);
     ShaderProc32 chooseShaderProc32();
 
-    void possiblyScaleImage();
+    // returns false if we did not try to scale the image. In that case, we
+    // will need to "lock" its pixels some other way.
+    bool possiblyScaleImage();
+
+    // returns false if we failed to "lock" the pixels at all. Typically this
+    // means we have to abort the shader.
+    bool lockBaseBitmap();
 
     SkBitmapFilter* fBitmapFilter;