Reland - Refactor signaling in RWP

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 1d6fc04ca6719ed8fd22f34093b7a35d3c8b4814..794141c9f744bb0e1ac12d97ce7dc12f67d03ddd 100644
--- a/content/renderer/raster_worker_pool.h
+++ b/content/renderer/raster_worker_pool.h
@@ -48,7 +48,8 @@ class CONTENT_EXPORT RasterWorkerPool : public base::TaskRunner,
 
   // Runs a task from one of the provided categories. Categories listed first
   // have higher priority.
-  void Run(const std::vector<cc::TaskCategory>& categories);
+  void Run(const std::vector<cc::TaskCategory>& categories,
+           base::ConditionVariable* work_ready_cv);
 
   void FlushForTesting();
 
@@ -102,6 +103,14 @@ class CONTENT_EXPORT RasterWorkerPool : public base::TaskRunner,
     DISALLOW_COPY_AND_ASSIGN(ClosureTask);
   };
 
+  // Helper function which signals the CV for the next task to run.
+  void SignalHasReadyToRunTasksWithLockAcquired();
+
+  // Determines if we should run a new task for the given category. This factors
+  // in whether a task is available and whether the count of running tasks is
+  // low enough to start a new one.
+  bool ShouldRunTaskForCategoryWithLockAcquired(cc::TaskCategory category);
+
   void ScheduleTasksWithLockAcquired(cc::NamespaceToken token,
                                      cc::TaskGraph* graph);
   void CollectCompletedTasksWithLockAcquired(cc::NamespaceToken token,
@@ -124,9 +133,9 @@ class CONTENT_EXPORT RasterWorkerPool : public base::TaskRunner,
   // Cached vector to avoid allocation when getting the list of complete
   // tasks.
   cc::Task::Vector completed_tasks_;
-  // Condition variable that is waited on by Run() until new tasks are ready to
-  // run or shutdown starts.
-  base::ConditionVariable has_ready_to_run_tasks_cv_;
+  // Condition variables for foreground and background tasks.
+  base::ConditionVariable foreground_has_ready_to_run_tasks_cv_;
+  base::ConditionVariable background_has_ready_to_run_tasks_cv_;
   // Condition variable that is waited on by origin threads until a namespace
   // has finished running all associated tasks.
   base::ConditionVariable has_namespaces_with_finished_running_tasks_cv_;