gpu: Reduce GL context switches used to check pending queries.

gpu/command_buffer/service/gpu_scheduler.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_GPU_SCHEDULER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GPU_SCHEDULER_H_
 
 #include <queue>
 
 #include "base/atomic_ref_count.h"
@@ skipping 55 matching lines @@
 
   // Sets whether commands should be processed by this scheduler. Setting to
   // false unschedules. Setting to true reschedules. Whether or not the
   // scheduler is currently scheduled is "reference counted". Every call with
   // false must eventually be paired by a call with true.
   void SetScheduled(bool is_scheduled);
 
   // Returns whether the scheduler is currently able to process more commands.
   bool IsScheduled();
 
-  // Returns whether the scheduler needs to be polled again in the future.
-  bool HasMoreWork();
+  // Returns whether the scheduler needs to be polled again in the future to
+  // process pending queries.
+  bool HasPendingQueries() const;
+
+  // Process pending queries and return. HasPendingQueries() can be used to
+  // determine if there's more pending queries after this has been called.
+  void ProcessPendingQueries();
 
   typedef base::Callback<void(bool /* scheduled */)> SchedulingChangedCallback;
 
   // Sets a callback that is invoked just before scheduler is rescheduled
   // or descheduled. Takes ownership of callback object.
   void SetSchedulingChangedCallback(const SchedulingChangedCallback& callback);
 
   // Implementation of CommandBufferEngine.
   scoped_refptr<Buffer> GetSharedMemoryBuffer(int32 shm_id) override;
   void set_token(int32 token) override;
   bool SetGetBuffer(int32 transfer_buffer_id) override;
   bool SetGetOffset(int32 offset) override;
   int32 GetGetOffset() override;
 
   void SetCommandProcessedCallback(const base::Closure& callback);
 
-  bool HasMoreIdleWork();
+  // Returns whether the scheduler needs to be polled again in the future to
+  // process idle work.
+  bool HasMoreIdleWork() const;
+
+  // Perform some idle work and return. HasMoreIdleWork() can be used to
+  // determine if there's more idle work do be done after this has been called.
   void PerformIdleWork();
 
   CommandParser* parser() const {
     return parser_.get();
   }
 
   bool IsPreempted();
 
  private:
   // Artificially reschedule if the scheduler is still unscheduled after a
@@ skipping 36 matching lines @@
   // A factory for outstanding rescheduling tasks that is invalidated whenever
   // the scheduler is rescheduled.
   base::WeakPtrFactory<GpuScheduler> reschedule_task_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuScheduler);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GPU_SCHEDULER_H_