DM: some refactoring

dm/DMComparisonTask.cpp

Index: dm/DMComparisonTask.cpp
diff --git a/dm/DMComparisonTask.cpp b/dm/DMComparisonTask.cpp
deleted file mode 100644
index bb4e656754325d0b07e52a16a214e87329dba99a..0000000000000000000000000000000000000000
--- a/dm/DMComparisonTask.cpp
+++ /dev/null
@@ -1,21 +0,0 @@
-#include "DMComparisonTask.h"
-#include "DMUtil.h"
-
-namespace DM {
-
-ComparisonTask::ComparisonTask(const Task& parent,
-                               skiagm::Expectations expectations,
-                               SkBitmap bitmap)
-    : Task(parent)
-    , fName(parent.name())  // Masquerade as parent so failures are attributed to it.
-    , fExpectations(expectations)
-    , fBitmap(bitmap)
-    {}
-
-void ComparisonTask::draw() {
-    if (!MeetsExpectations(fExpectations, fBitmap)) {
-        this->fail();
-    }
-}
-
-}  // namespace DM