Revert of Sketch DM refactor.

dm/DMTask.h

+#ifndef DMTask_DEFINED
+#define DMTask_DEFINED
+
+#include "DMGpuSupport.h"
+#include "DMReporter.h"
+#include "SkRunnable.h"
+#include "SkTaskGroup.h"
+#include "SkTime.h"
+
+// DM will run() these tasks on one of two threadpools.
+// Subclasses can call fail() to mark this task as failed, or make any number of spawnChild() calls
+// to kick off dependent tasks.
+//
+// Tasks delete themselves when run.
+
+namespace DM {
+
+class TaskRunner;
+
+class CpuTask;
+
+class Task {
+public:
+    virtual bool shouldSkip() const = 0;
+    virtual SkString name() const = 0;
+
+    // Returns the number of parents above this task.
+    // Top-level tasks return 0, their children 1, and so on.
+    int depth() const { return fDepth; }
+
+protected:
+    Task(Reporter* reporter, TaskRunner* taskRunner);
+    Task(const Task& parent);
+    virtual ~Task();
+
+    void start();
+    void fail(const char* msg = NULL);
+    void finish();
+
+    void reallySpawnChild(CpuTask* task);  // For now we don't allow GPU child tasks.
+
+private:
+    Reporter* fReporter;      // Unowned.
+    TaskRunner* fTaskRunner;  // Unowned.
+    int fDepth;
+    SkMSec fStart;
+};
+
+class CpuTask : public Task, public SkRunnable {
+public:
+    CpuTask(Reporter* reporter, TaskRunner* taskRunner);
+    CpuTask(const Task& parent);
+    virtual ~CpuTask() {}
+
+    void run() SK_OVERRIDE;
+    virtual void draw() = 0;
+
+    void spawnChild(CpuTask* task);
+};
+
+class GpuTask : public Task {
+ public:
+    GpuTask(Reporter* reporter, TaskRunner* taskRunner);
+    virtual ~GpuTask() {}
+
+    void run(GrContextFactory*);
+    virtual void draw(GrContextFactory*) = 0;
+
+    void spawnChild(CpuTask* task);
+};
+
+}  // namespace DM
+
+#endif  // DMTask_DEFINED