dm is like gm, but faster and with fewer features.

This is sort of the near-minimal proof-of-concept skeleton.

  - It can run existing GMs.
  - It supports most configs (just not PDF).
  - --replay is the only "fancy" feature it currently supports

Hopefully you will be disturbed by its speed.

BUG=
R=epoger@google.com

Review URL: https://codereview.chromium.org/22839016

git-svn-id: http://skia.googlecode.com/svn/trunk@11802 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/dm/DMComparisonTask.h b/dm/DMComparisonTask.h
new file mode 100644
index 0000000..265a58c
--- /dev/null
+++ b/dm/DMComparisonTask.h
@@ -0,0 +1,31 @@
+#ifndef DMComparisonTask_DEFINED
+#define DMComparisonTask_DEFINED
+
+#include "DMTask.h"
+#include "SkBitmap.h"
+#include "SkString.h"
+#include "gm_expectations.h"
+
+namespace DM {
+
+// We use ComparisonTask to move CPU-bound comparison work of GpuTasks back to
+// the main thread pool, where we probably have more threads available.
+
+class ComparisonTask : public Task {
+public:
+    ComparisonTask(const Task& parent, skiagm::Expectations, SkBitmap);
+
+    virtual void draw() SK_OVERRIDE;
+    virtual bool usesGpu() const SK_OVERRIDE { return false; }
+    virtual bool shouldSkip() const SK_OVERRIDE { return false; }
+    virtual SkString name() const SK_OVERRIDE { return fName; }
+
+private:
+    const SkString fName;
+    const skiagm::Expectations fExpectations;
+    const SkBitmap fBitmap;
+};
+
+}  // namespace DM
+
+#endif  // DMComparisonTask_DEFINED