Work (in progress) to make SkShader immutable.

src/core/SkBitmapProcShader.h

Index: src/core/SkBitmapProcShader.h
diff --git a/src/core/SkBitmapProcShader.h b/src/core/SkBitmapProcShader.h
index 7a4ddb45ab6587334a99e6ea1cf03ef8c99b49f8..573c04d5f8a93dbd3dd3ac45e7c9e7b1a4ab9ccb 100644
--- a/src/core/SkBitmapProcShader.h
+++ b/src/core/SkBitmapProcShader.h
@@ -49,10 +49,10 @@ private:
     typedef SkShader INHERITED;
 };
 
-// Commonly used allocator. It currently is only used to allocate up to 2 objects. The total
+// Commonly used allocator. It currently is only used to allocate up to 3 objects. The total
 // bytes requested is calculated using one of our large shaders plus the size of an Sk3DBlitter
 // in SkDraw.cpp
-typedef SkSmallAllocator<2, sizeof(SkBitmapProcShader) + sizeof(void*) * 2> SkTBlitterAllocator;
+typedef SkSmallAllocator<3, sizeof(SkBitmapProcShader) + sizeof(void*) * 2> SkTBlitterAllocator;
 
 // If alloc is non-NULL, it will be used to allocate the returned SkShader, and MUST outlive
 // the SkShader.