Remove unsafe mode to enable es3 api by default for WebGL2 and ES3 context

content/common/gpu_host_messages.h

 // Copyright 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.
 
 // Multiply-included message file, hence no include guard here, but see below
 // for a much smaller-than-usual include guard section.
 
 #include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "content/common/establish_channel_params.h"
@@ skipping 77 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(disable_gpu_program_cache)
   IPC_STRUCT_TRAITS_MEMBER(enforce_gl_minimums)
   IPC_STRUCT_TRAITS_MEMBER(force_gpu_mem_available)
   IPC_STRUCT_TRAITS_MEMBER(gpu_program_cache_size)
   IPC_STRUCT_TRAITS_MEMBER(disable_gpu_shader_disk_cache)
   IPC_STRUCT_TRAITS_MEMBER(enable_threaded_texture_mailboxes)
   IPC_STRUCT_TRAITS_MEMBER(gl_shader_interm_output)
   IPC_STRUCT_TRAITS_MEMBER(emulate_shader_precision)
   IPC_STRUCT_TRAITS_MEMBER(enable_gpu_service_logging)
   IPC_STRUCT_TRAITS_MEMBER(enable_gpu_service_tracing)
-  IPC_STRUCT_TRAITS_MEMBER(enable_unsafe_es3_apis)
   IPC_STRUCT_TRAITS_MEMBER(use_passthrough_cmd_decoder)
 IPC_STRUCT_TRAITS_END()
 
 //------------------------------------------------------------------------------
 // GPU Messages
 // These are messages from the browser to the GPU process.
 
 // Tells the GPU process to initialize itself. The browser explicitly
 // requests this be done so that we are guaranteed that the channel is set
 // up between the browser and GPU process before doing any work that might
@@ skipping 115 matching lines @@
 IPC_MESSAGE_CONTROL1(GpuHostMsg_DidDestroyOffscreenContext, GURL /* url */)
 
 // Message from GPU to add a GPU log message to the about:gpu page.
 IPC_MESSAGE_CONTROL3(GpuHostMsg_OnLogMessage,
                      int /*severity*/,
                      std::string /* header */,
                      std::string /* message */)
 
 // Sent by the GPU process to indicate that a fields trial has been activated.
 IPC_MESSAGE_CONTROL1(GpuHostMsg_FieldTrialActivated, std::string /* name */)