Refactoring of GPU NormalMap handling out into its own class

src/core/SkBitmapProcShader.cpp

Index: src/core/SkBitmapProcShader.cpp
diff --git a/src/core/SkBitmapProcShader.cpp b/src/core/SkBitmapProcShader.cpp
index 972d73173fc4847b82fede1480f7dafaf9a7fc9a..e7e2e11d97f8abbb9fe6e5bdef96526f2147ed23 100644
--- a/src/core/SkBitmapProcShader.cpp
+++ b/src/core/SkBitmapProcShader.cpp
@@ -303,6 +303,16 @@ bool SkBitmapProcShader::isOpaque() const {
     return fRawBitmap.isOpaque();
 }
 
+bool SkBitmapProcShader::bitmapIsTooBig(const SkBitmap& bm) {
+    // SkBitmapProcShader stores bitmap coordinates in a 16bit buffer, as it
+    // communicates between its matrix-proc and its sampler-proc. Until we can
+    // widen that, we have to reject bitmaps that are larger.
+    //
+    static const int kMaxSize = 65535;
+
+    return bm.width() > kMaxSize || bm.height() > kMaxSize;
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 #include "SkUnPreMultiply.h"