Handle CONTEXT LOST issue with Queries

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 459 matching lines @@
 
   bool IsExtensionAvailable(const char* ext);
 
   // Caches certain capabilties state. Return true if cached.
   bool SetCapabilityState(GLenum cap, bool enabled);
 
   IdHandlerInterface* GetIdHandler(int id_namespace) const;
 
   void FinishHelper();
 
+  // Checks if the context is lost.
+  // NOTE: This is an expensive call and should only be called
+  // for error checking.
+  bool MustBeContextLost();
+
   GLES2Util util_;
   GLES2CmdHelper* helper_;
   TransferBufferInterface* transfer_buffer_;
   std::string last_error_;
 
   std::queue<int32> swap_buffers_tokens_;
   std::queue<int32> rate_limit_tokens_;
 
   ExtensionStatus angle_pack_reverse_row_order_status;
 
@@ skipping 70 matching lines @@
 
   scoped_ptr<MappedMemoryManager> mapped_memory_;
 
   scoped_refptr<ShareGroup> share_group_;
 
   scoped_ptr<QueryTracker> query_tracker_;
   QueryTracker::Query* current_query_;
 
   ErrorMessageCallback* error_message_callback_;
 
+  bool context_lost_;
+
   DISALLOW_COPY_AND_ASSIGN(GLES2Implementation);
 };
 
 inline bool GLES2Implementation::GetBufferParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 inline bool GLES2Implementation::GetFramebufferAttachmentParameterivHelper(
     GLenum /* target */,
@@ skipping 20 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_