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/DMTask.h b/dm/DMTask.h
new file mode 100644
index 0000000..744fd6b
--- /dev/null
+++ b/dm/DMTask.h
@@ -0,0 +1,43 @@
+#ifndef DMTask_DEFINED
+#define DMTask_DEFINED
+
+#include "DMReporter.h"
+#include "SkRunnable.h"
+#include "SkThreadPool.h"
+
+// DM will run() these tasks on one of two threadpools, depending on the result
+// of usesGpu().  The subclasses can call fail() to mark this task as failed,
+// or make any number of spawnChild() calls to kick off dependent tasks.
+//
+// Task deletes itself when run.
+
+namespace DM {
+
+class TaskRunner;
+
+class Task : public SkRunnable {
+public:
+    Task(Reporter* reporter, TaskRunner* taskRunner);
+    Task(const Task& that);
+    virtual ~Task();
+
+    void run();
+
+    virtual void draw() = 0;
+    virtual bool usesGpu() const = 0;
+    virtual bool shouldSkip() const = 0;
+    virtual SkString name() const = 0;
+
+protected:
+    void spawnChild(Task* task);
+    void fail();
+
+private:
+    // Both unowned.
+    Reporter* fReporter;
+    TaskRunner* fTaskRunner;
+};
+
+}  // namespace DM
+
+#endif  // DMTask_DEFINED