gpu: Support parallel active queries in command buffer

gpu/command_buffer/client/gles2_implementation.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_CLIENT_GLES2_IMPLEMENTATION_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 
 #include <GLES2/gl2.h>
 
 #include <map>
@@ skipping 680 matching lines @@
   MappedBufferMap mapped_buffers_;
 
   typedef std::map<const void*, MappedTexture> MappedTextureMap;
   MappedTextureMap mapped_textures_;
 
   scoped_ptr<MappedMemoryManager> mapped_memory_;
 
   scoped_refptr<ShareGroup> share_group_;
 
   scoped_ptr<QueryTracker> query_tracker_;
-  QueryTracker::Query* current_query_;
+  typedef std::map<GLuint, QueryTracker::Query*> QueryMap;
+  QueryMap current_queries_;
 
   scoped_ptr<BufferTracker> buffer_tracker_;
 
   scoped_ptr<GpuMemoryBufferTracker> gpu_memory_buffer_tracker_;
 
   ErrorMessageCallback* error_message_callback_;
 
   scoped_ptr<std::string> current_trace_name_;
 
   GpuControl* gpu_control_;
@@ skipping 41 matching lines @@
 
 inline bool GLES2Implementation::GetTexParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_