DM: duh, don't calculate digests unless we're going to look at them.

This doesn't cut the runtime significantly (~6s either way) but it does cut the CPU time down from ~10s to ~6s.

BUG=
R=bungeman@google.com

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/27476007

git-svn-id: http://skia.googlecode.com/svn/trunk@11826 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/dm/DMCpuTask.cpp b/dm/DMCpuTask.cpp
index 544f73c..14f661a 100644
--- a/dm/DMCpuTask.cpp
+++ b/dm/DMCpuTask.cpp
@@ -33,14 +33,13 @@
     fGM->draw(&canvas);
     canvas.flush();
 
-    const skiagm::GmResultDigest digest(bitmap);
-    if (!meetsExpectations(fExpectations, digest)) {
+    if (!meetsExpectations(fExpectations, bitmap)) {
         this->fail();
     }
 
     if (FLAGS_replay) {
         this->spawnChild(SkNEW_ARGS(ReplayTask,
-                                   ("replay", *this, fGMFactory(NULL), digest, fConfig)));
+                                   ("replay", *this, fGMFactory(NULL), bitmap)));
     }
 }