Plumb Task Scheduler Histograms to the Task Scheduler Internals Page

base/task_scheduler/task_scheduler.h

Index: base/task_scheduler/task_scheduler.h
diff --git a/base/task_scheduler/task_scheduler.h b/base/task_scheduler/task_scheduler.h
index 91a608ec746e65e2ebe85475ac377d0d845f4ba9..fe3d5e53ee919fe4ebfedbd1b10ef06ad6c3283b 100644
--- a/base/task_scheduler/task_scheduler.h
+++ b/base/task_scheduler/task_scheduler.h
@@ -20,6 +20,7 @@ class Location;
 
 namespace base {
 
+class HistogramBase;
 class SchedulerWorkerPoolParams;
 
 // Interface for a task scheduler and static methods to manage the instance used
@@ -48,6 +49,9 @@ class BASE_EXPORT TaskScheduler {
       const TaskTraits& traits,
       ExecutionMode execution_mode) = 0;
 
+  // Returns a vector of all histograms available in this task scheduler.
+  virtual std::vector<const HistogramBase*> GetHistograms() const = 0;
+
   // Synchronously shuts down the scheduler. Once this is called, only tasks
   // posted with the BLOCK_SHUTDOWN behavior will be run. When this returns:
   // - All SKIP_ON_SHUTDOWN tasks that were already running have completed their