SkDiscardableMemoryPool to abstract class

Motivation - we want to keep our public headers small.

R=scroggo@google.com, reed@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/223403012

git-svn-id: http://skia.googlecode.com/svn/trunk@14063 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/factory.cpp b/gm/factory.cpp
index efd817d..29cf7ea 100644
--- a/gm/factory.cpp
+++ b/gm/factory.cpp
@@ -35,7 +35,7 @@
             // Create a cache which will boot the pixels out anytime the
             // bitmap is unlocked.
             SkAutoTUnref<SkDiscardableMemoryPool> pool(
-                SkNEW_ARGS(SkDiscardableMemoryPool, (1)));
+                SkDiscardableMemoryPool::Create(1));
             SkAssertResult(SkInstallDiscardablePixelRef(
                 SkDecodingImageGenerator::Create(
                     data, SkDecodingImageGenerator::Options()),