Add category handling to RasterWorkerPool

content/renderer/raster_worker_pool.h

Index: content/renderer/raster_worker_pool.h
diff --git a/content/renderer/raster_worker_pool.h b/content/renderer/raster_worker_pool.h
index 1b7cfb1b54320dc848c6806a48ca2356a30bf5c6..a4222c7938d85eda0a1aacc71d1366acc836cdd7 100644
--- a/content/renderer/raster_worker_pool.h
+++ b/content/renderer/raster_worker_pool.h
@@ -13,6 +13,7 @@
 #include "base/synchronization/condition_variable.h"
 #include "base/task_runner.h"
 #include "base/threading/simple_thread.h"
+#include "cc/raster/task_category.h"
 #include "cc/raster/task_graph_runner.h"
 #include "cc/raster/task_graph_work_queue.h"
 #include "content/common/content_export.h"
@@ -27,10 +28,8 @@ namespace content {
 // parallel with other instances of sequenced task runners.
 // It's also possible to get the underlying TaskGraphRunner to schedule a graph
 // of tasks with their dependencies.
-class CONTENT_EXPORT RasterWorkerPool
-    : public base::TaskRunner,
-      public cc::TaskGraphRunner,
-      public base::DelegateSimpleThread::Delegate {
+class CONTENT_EXPORT RasterWorkerPool : public base::TaskRunner,
+                                        public cc::TaskGraphRunner {
  public:
   RasterWorkerPool();
 
@@ -47,14 +46,16 @@ class CONTENT_EXPORT RasterWorkerPool
   void CollectCompletedTasks(cc::NamespaceToken token,
                              cc::Task::Vector* completed_tasks) override;
 
-  // Overridden from base::DelegateSimpleThread::Delegate:
-  void Run() override;
+  // Runs a task from one of the provided categories. Categories listed first
+  // have higher priority.
+  void Run(const std::vector<cc::TaskCategory>& categories);
 
   void FlushForTesting();
 
   // Spawn |num_threads| number of threads and start running work on the
   // worker threads.
   void Start(int num_threads,
+             bool use_single_thread_for_background_raster_tasks,
              const base::SimpleThread::Options& thread_options);
 
   // Finish running all the posted tasks (and nested task posted by those tasks)
@@ -75,9 +76,9 @@ class CONTENT_EXPORT RasterWorkerPool
   class RasterWorkerPoolSequencedTaskRunner;
   friend class RasterWorkerPoolSequencedTaskRunner;
 
-  // Run next task. Caller must acquire |lock_| prior to calling this function.
-  // Returns true if there was a task available to run.
-  bool RunTaskWithLockAcquired();
+  // Run next task. Caller must acquire |lock_| prior to calling this function
+  // and make sure at least one task is ready to run.
+  void RunTaskWithLockAcquired(cc::TaskCategory category);
 
   // Simple Task for the TaskGraphRunner that wraps a closure.
   // This class is used to schedule TaskRunner tasks on the
@@ -104,7 +105,7 @@ class CONTENT_EXPORT RasterWorkerPool
                                              cc::Task::Vector* completed_tasks);
 
   // The actual threads where work is done.
-  ScopedVector<base::DelegateSimpleThread> threads_;
+  std::vector<scoped_ptr<base::SimpleThread>> threads_;
 
   // Lock to exclusively access all the following members that are used to
   // implement the TaskRunner and TaskGraphRunner interfaces.