detect gigantoid matrices, and do nothing to avoid wacky overflows from float -> int

https://code.google.com/p/chromium/issues/detail?id=156231
Review URL: https://codereview.appspot.com/6842075

git-svn-id: http://skia.googlecode.com/svn/trunk@6513 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkBitmapProcState.h b/src/core/SkBitmapProcState.h
index 60cb926..4181519 100644
--- a/src/core/SkBitmapProcState.h
+++ b/src/core/SkBitmapProcState.h
@@ -138,7 +138,9 @@
     MatrixProc chooseMatrixProc(bool trivial_matrix);
     bool chooseProcs(const SkMatrix& inv, const SkPaint&);
     ShaderProc32 chooseShaderProc32();
-    void setupForTranslate();
+    
+    // Return false if we failed to setup for fast translate (e.g. overflow)
+    bool setupForTranslate();
 
 #ifdef SK_DEBUG
     static void DebugMatrixProc(const SkBitmapProcState&,