Perform glReadPixels with PBOs in the gpu, if PBOs are available.

gpu/command_buffer/service/query_manager.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_QUERY_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_QUERY_MANAGER_H_
 
 #include <deque>
+#include <vector>
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "gpu/command_buffer/service/feature_info.h"
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/gpu_export.h"
 
 namespace gpu {
@@ skipping 41 matching lines @@
     virtual bool Begin() = 0;
 
     // Returns false if shared memory for sync is invalid.
     virtual bool End(uint32 submit_count) = 0;
 
     // Returns false if shared memory for sync is invalid.
     virtual bool Process() = 0;
 
     virtual void Destroy(bool have_context) = 0;
 
+    void AddCallback(base::Closure callback);
+
    protected:
     virtual ~Query();
 
     QueryManager* manager() const {
       return manager_;
     }
 
     void MarkAsDeleted() {
       deleted_ = true;
     }
@@ skipping 32 matching lines @@
 
     uint32 submit_count() const {
       return submit_count_;
     }
 
    private:
     friend class QueryManager;
     friend class QueryManagerTest;
     friend class base::RefCounted<Query>;
 
+    void RunCallbacks();
+
     // The manager that owns this Query.
     QueryManager* manager_;
 
     // The type of query.
     GLenum target_;
 
     // The shared memory used with this Query.
     int32 shm_id_;
     uint32 shm_offset_;
 
     // Count to set process count do when completed.
     uint32 submit_count_;
 
     // True if in the queue.
     bool pending_;
 
     // True if deleted.
     bool deleted_;
+
+    // List of callbacks to run when result is available.
+    std::vector<base::Closure> callbacks_;
   };
 
   QueryManager(
       GLES2Decoder* decoder,
       FeatureInfo* feature_info);
   ~QueryManager();
 
   // Must call before destruction.
   void Destroy(bool have_context);
 
@@ skipping 77 matching lines @@
   // Async pixel transfer queries waiting for completion.
   QueryQueue pending_transfer_queries_;
 
   DISALLOW_COPY_AND_ASSIGN(QueryManager);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_QUERY_MANAGER_H_