Always use Desktop GL 4.1 or less BindBufferRange behavior.

gpu/command_buffer/service/transform_feedback_manager.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.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_TRANSFORM_FEEDBACK_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_TRANSFORM_FEEDBACK_MANAGER_H_
 
 #include <vector>
 
 #include "base/containers/hash_tables.h"
@@ skipping 58 matching lines @@
 
   bool active_;
   bool paused_;
 
   GLenum primitive_mode_;
 };
 
 // This class keeps tracks of the transform feedbacks and their states.
 class GPU_EXPORT TransformFeedbackManager {
  public:
-  // |needs_emulation| is true on Desktop GL 4.1 or lower.
+  // In theory |needs_emulation| needs to be true on Desktop GL 4.1 or lower.
+  // However, we set it to true everywhere, not to trust drivers to handle
+  // out-of-bounds buffer accesses.
   TransformFeedbackManager(GLuint max_transform_feedback_separate_attribs,
                            bool needs_emulation);
   ~TransformFeedbackManager();
 
   void MarkContextLost() {
     lost_context_ = true;
   }
 
   // Must call before destruction.
   void Destroy();
@@ skipping 30 matching lines @@
   bool needs_emulation_;
   bool lost_context_;
 
   DISALLOW_COPY_AND_ASSIGN(TransformFeedbackManager);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_TRANSFORM_FEEDBACK_MANAGER_H_