add peekPixels to SkCanvas and SkSurface

fix reference to SkBaseDevice, which was only a problem in no-gpu build

This reverts commit 4fa44a6bf73891b21917fb90d02beef9143bffa3.

R=reed@google.com

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/163603003

git-svn-id: http://skia.googlecode.com/svn/trunk@13432 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/ninepatchstretch.cpp b/gm/ninepatchstretch.cpp
index a14af00..74cc87f 100644
--- a/gm/ninepatchstretch.cpp
+++ b/gm/ninepatchstretch.cpp
@@ -13,10 +13,7 @@
     const int kSize = 2*kFixed + kStretchy;
 
     bitmap->allocN32Pixels(kSize, kSize);
-    SkBaseDevice* dev = new SkBitmapDevice(*bitmap);
-
-    SkCanvas canvas(dev);
-    dev->unref();
+    SkCanvas canvas(*bitmap);
     canvas.clear(SK_ColorTRANSPARENT);
 
     SkRect r = SkRect::MakeWH(SkIntToScalar(kSize), SkIntToScalar(kSize));