Split SkDevice out of SkBitmapDevice

https://codereview.chromium.org/22978012/



git-svn-id: http://skia.googlecode.com/svn/trunk@10830 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/lighting.cpp b/gm/lighting.cpp
index f16e781..a89a7f1 100644
--- a/gm/lighting.cpp
+++ b/gm/lighting.cpp
@@ -27,7 +27,7 @@
     void make_bitmap() {
         fBitmap.setConfig(SkBitmap::kARGB_8888_Config, 100, 100);
         fBitmap.allocPixels();
-        SkDevice device(fBitmap);
+        SkBitmapDevice device(fBitmap);
         SkCanvas canvas(&device);
         canvas.clear(0x00000000);
         SkPaint paint;