Remove GrRefCnt.h in favor of SkRefCnt.h

This removes GrRefCnt.h with all its tyepdefs and #defines and just switch them
to the Sk* equivalents.

GrSafeSetNull was promoted to SkSafeSetNull in SkRefCnt.h.

BUG=None
TEST=none, no functional changes.
R=bsalomon@google.com, robertphillips@google.com

Author: tfarina@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23904003

git-svn-id: http://skia.googlecode.com/svn/trunk@11151 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/ReadWriteAlphaTest.cpp b/tests/ReadWriteAlphaTest.cpp
index 8ae936e..fb177df 100644
--- a/tests/ReadWriteAlphaTest.cpp
+++ b/tests/ReadWriteAlphaTest.cpp
@@ -46,7 +46,7 @@
             return;
         }
 
-        GrAutoUnref au(texture);
+        SkAutoUnref au(texture);
 
         // create a distinctive texture
         for (int y = 0; y < Y_SIZE; ++y) {