Don't let Pepper GL create ES3 contexts

content/renderer/pepper/ppb_graphics_3d_impl.cc

 // 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.
 
 #include "content/renderer/pepper/ppb_graphics_3d_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/location.h"
@@ skipping 231 matching lines @@
 
   scoped_refptr<gpu::GpuChannelHost> channel =
       render_thread->EstablishGpuChannelSync();
   if (!channel)
     return false;
 
   has_alpha_ = requested_attribs.alpha_size > 0;
 
   gpu::gles2::ContextCreationAttribHelper attrib_helper = requested_attribs;
   attrib_helper.should_use_native_gmb_for_backbuffer = use_image_chromium_;
+  attrib_helper.context_type = gpu::gles2::CONTEXT_TYPE_OPENGLES2;
 
   gpu::CommandBufferProxyImpl* share_buffer = NULL;
   if (share_context) {
     PPB_Graphics3D_Impl* share_graphics =
         static_cast<PPB_Graphics3D_Impl*>(share_context);
     share_buffer = share_graphics->GetCommandBufferProxy();
   }
 
   command_buffer_ = gpu::CommandBufferProxyImpl::Create(
       std::move(channel), gpu::kNullSurfaceHandle, share_buffer,
@@ skipping 92 matching lines @@
   if (!mailboxes_to_reuse_.empty()) {
     gpu::Mailbox mailbox = mailboxes_to_reuse_.back();
     mailboxes_to_reuse_.pop_back();
     return mailbox;
   }
 
   return gpu::Mailbox::Generate();
 }
 
 }  // namespace content