Remove expectations / -r from DM entirely.

dm/DMExpectations.h

Index: dm/DMExpectations.h
diff --git a/dm/DMExpectations.h b/dm/DMExpectations.h
deleted file mode 100644
index 7993a55be965244f07f92a38eaefebcff65dab06..0000000000000000000000000000000000000000
--- a/dm/DMExpectations.h
+++ /dev/null
@@ -1,19 +0,0 @@
-#ifndef DMExpectations_DEFINED
-#define DMExpectations_DEFINED
-
-#include "DMTask.h"
-
-namespace DM {
-
-struct Expectations {
-    virtual ~Expectations() {}
-
-    // Return true if bitmap is the correct output for task, else false.
-    virtual bool check(const Task& task, SkBitmap bitmap) const {
-        return true;
-    }
-};
-
-}  // namespace DM
-
-#endif // DMExpectations_DEFINED