Revert of Sketch DM refactor.

dm/DMTask.cpp

+#include "DMTask.h"
+#include "DMTaskRunner.h"
+#include "SkCommonFlags.h"
+
+namespace DM {
+
+Task::Task(Reporter* reporter, TaskRunner* taskRunner)
+    : fReporter(reporter)
+    , fTaskRunner(taskRunner)
+    , fDepth(0) {
+    fReporter->taskCreated();
+}
+
+Task::Task(const Task& parent)
+    : fReporter(parent.fReporter)
+    , fTaskRunner(parent.fTaskRunner)
+    , fDepth(parent.depth() + 1) {
+    fReporter->taskCreated();
+}
+
+Task::~Task() {
+    fReporter->taskDestroyed();
+}
+
+void Task::fail(const char* msg) {
+    SkString failure(this->name());
+    if (msg) {
+        failure.appendf(": %s", msg);
+    }
+    fReporter->fail(failure);
+}
+
+void Task::start() {
+    fStart = SkTime::GetMSecs();
+}
+
+void Task::finish() {
+    fReporter->printStatus(this->name(), SkTime::GetMSecs() - fStart);
+}
+
+void Task::reallySpawnChild(CpuTask* task) {
+    fTaskRunner->add(task);
+}
+
+CpuTask::CpuTask(Reporter* reporter, TaskRunner* taskRunner) : Task(reporter, taskRunner) {}
+CpuTask::CpuTask(const Task& parent) : Task(parent) {}
+
+void CpuTask::run() {
+    // If the task says skip, or if we're starting a top-level CPU task and we don't want to, skip.
+    const bool skip = this->shouldSkip() || (this->depth() == 0 && !FLAGS_cpu);
+    if (!skip) {
+        this->start();
+        if (!FLAGS_dryRun) this->draw();
+        this->finish();
+    }
+    SkDELETE(this);
+}
+
+void CpuTask::spawnChild(CpuTask* task) {
+    // Run children serially on this (CPU) thread.  This tends to save RAM and is usually no slower.
+    // Calling reallySpawnChild() is nearly equivalent, but it'd pointlessly contend on the
+    // threadpool; reallySpawnChild() is most useful when you want to change threadpools.
+    task->run();
+}
+
+GpuTask::GpuTask(Reporter* reporter, TaskRunner* taskRunner) : Task(reporter, taskRunner) {}
+
+void GpuTask::run(GrContextFactory* factory) {
+    // If the task says skip, or if we're starting a top-level GPU task and we don't want to, skip.
+    const bool skip = this->shouldSkip() || (this->depth() == 0 && !FLAGS_gpu);
+    if (!skip) {
+        this->start();
+        if (!FLAGS_dryRun) this->draw(factory);
+        this->finish();
+        if (FLAGS_abandonGpuContext) {
+            factory->abandonContexts();
+        }
+        if (FLAGS_resetGpuContext || FLAGS_abandonGpuContext) {
+            factory->destroyContexts();
+        }
+    }
+    SkDELETE(this);
+}
+
+void GpuTask::spawnChild(CpuTask* task) {
+    // Spawn a new task so it runs on the CPU threadpool instead of the GPU one we're on now.
+    // It goes on the front of the queue to minimize the time we must hold reference bitmaps in RAM.
+    this->reallySpawnChild(task);
+}
+
+}  // namespace DM