Test dynamic priorities

cc/raster/task_graph_runner.h

Index: cc/raster/task_graph_runner.h
diff --git a/cc/raster/task_graph_runner.h b/cc/raster/task_graph_runner.h
index 23094ef5a7ef3c81a6cae0fbde931c57c11efe98..aa36526e5ed475d5562314e750d1dd805c65f4c8 100644
--- a/cc/raster/task_graph_runner.h
+++ b/cc/raster/task_graph_runner.h
@@ -15,7 +15,10 @@
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/threading/simple_thread.h"
+#include "base/time/time.h"
 #include "cc/base/cc_export.h"
+#include "cc/raster/task_category.h"
 
 namespace cc {
 
@@ -33,6 +36,11 @@ class CC_EXPORT Task : public base::RefCountedThreadSafe<Task> {
   // safety.
   virtual void RunOnWorkerThread() = 0;
 
+  virtual bool IsRasterTask() { return false; }
+
+  void SetRunner(base::TestSimpleThread* runner) { runner_ = runner; }
+  base::TestSimpleThread* GetRunner() { return runner_; }
+
   void WillRun();
   void DidRun();
   bool HasFinishedRunning() const;
@@ -45,6 +53,8 @@ class CC_EXPORT Task : public base::RefCountedThreadSafe<Task> {
 
   bool will_run_;
   bool did_run_;
+
+  base::TestSimpleThread* runner_;
 };
 
 // A task dependency graph describes the order in which to execute a set