Move threadpool code from include/utils to tools/threadpool.

dm/DMTask.h

Index: dm/DMTask.h
diff --git a/dm/DMTask.h b/dm/DMTask.h
index 32bb9486f5e1c08c3ceaca27eb4b7c98d7650634..38dbf2f9ec4a489cc9dfbe90b6f3d226ac1cfe7d 100644
--- a/dm/DMTask.h
+++ b/dm/DMTask.h
@@ -3,7 +3,7 @@
 
 #include "DMReporter.h"
 #include "DMGpuSupport.h"
-#include "SkRunnable.h"
+#include "Runnable.h"
 #include "SkTime.h"
 
 // DM will run() these tasks on one of two threadpools.
@@ -45,7 +45,7 @@ private:
     SkMSec fStart;
 };
 
-class CpuTask : public Task, public SkRunnable {
+class CpuTask : public Task, public Runnable {
 public:
     CpuTask(Reporter* reporter, TaskRunner* taskRunner);
     CpuTask(const Task& parent);
@@ -57,7 +57,7 @@ public:
     void spawnChild(CpuTask* task);
 };
 
-class GpuTask : public Task, public SkTRunnable<GrContextFactory> {
+class GpuTask : public Task, public TRunnable<GrContextFactory> {
  public:
     GpuTask(Reporter* reporter, TaskRunner* taskRunner);
     virtual ~GpuTask() {}