Check for some extensions before calling potentially NULL GL entry points.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough.h

 // Copyright (c) 2016 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.
 
 // This file contains the GLES2DecoderPassthroughImpl class.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_PASSTHROUGH_H_
 #define GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_PASSTHROUGH_H_
 
 #include "base/memory/ref_counted.h"
@@ skipping 269 matching lines @@
 
   void InsertError(GLenum error, const std::string& message);
   GLenum PopError();
   bool FlushErrors();
 
   bool IsEmulatedQueryTarget(GLenum target) const;
   error::Error ProcessQueries(bool did_finish);
 
   void UpdateTextureBinding(GLenum target, GLuint client_id, GLuint service_id);
 
+  void InitializeNativeCaps();
+
   int commands_to_process_;
 
   DebugMarkerManager debug_marker_manager_;
   Logger logger_;
 
 #define GLES2_CMD_OP(name) \
   Error Handle##name(uint32_t immediate_data_size, const volatile void* data);
 
   GLES2_COMMAND_LIST(GLES2_CMD_OP)
 #undef GLES2_CMD_OP
@@ skipping 70 matching lines @@
   // Currently active queries
   struct ActiveQuery {
     GLuint service_id = 0;
     int32_t shm_id = 0;
     uint32_t shm_offset = 0;
   };
   std::unordered_map<GLenum, ActiveQuery> active_queries_;
 
   std::set<GLenum> errors_;
 
+  // Native caps
+  bool has_es3_;
+  bool has_ext_discard_framebuffer_;
+  bool has_angle_framebuffer_multisample_;
+  bool has_ext_disjoint_timer_query_;
+  bool has_chromium_copy_texture_;
+  bool has_chromium_copy_compressed_texture_;

[Zhenyao Mo, 2017/02/13 18:12:08]

Can we consolidate these to FeatureInfo? It seems to be a better place for these
caps.

[Geoff Lang, 2017/02/13 19:53:06]

I tried but these features are enabled sometimes when the extension doesn't
exist.  For example, the FeatureInfo says that ext_discard_framebuffer is
present when the native extension exists or it's on es3 because it knows it can
be emulated.  I need to do a little extra tracking to know which native function
to call.

+
   // Cache of scratch memory
   std::vector<uint8_t> scratch_memory_;
 
 // Include the prototypes of all the doer functions from a separate header to
 // keep this file clean.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doer_prototypes.h"
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_GLES2_CMD_DECODER_PASSTHROUGH_H_