Split SkDevice into SkBaseDevice and SkBitmapDevice

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



git-svn-id: http://skia.googlecode.com/svn/trunk@10995 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/morphology.cpp b/gm/morphology.cpp
index 83de758..2d29fcd 100644
--- a/gm/morphology.cpp
+++ b/gm/morphology.cpp
@@ -28,7 +28,7 @@
     void make_bitmap() {
         fBitmap.setConfig(SkBitmap::kARGB_8888_Config, 135, 135);
         fBitmap.allocPixels();
-        SkDevice device(fBitmap);
+        SkBitmapDevice device(fBitmap);
         SkCanvas canvas(&device);
         canvas.clear(0x0);
         SkPaint paint;