Refactor context creation parameters into a struct.

gpu/gles2_conform_support/egl/context.cc

 // 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.
 
 #include "gpu/gles2_conform_support/egl/context.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "gpu/command_buffer/client/gles2_implementation.h"
@@ skipping 255 matching lines @@
       gpu::gles2::GLES2Decoder::Create(group.get()));
   if (!decoder.get())
     return false;
 
   std::unique_ptr<gpu::CommandExecutor> command_executor(
       new gpu::CommandExecutor(command_buffer.get(), decoder.get(),
                                decoder.get()));
 
   decoder->set_engine(command_executor.get());
 
+  gl::GLContextAttribs context_attribs;
+  context_attribs.gpu_preference = gl::PreferDiscreteGpu;
   scoped_refptr<gl::GLContext> gl_context(
-      gl::init::CreateGLContext(nullptr, gl_surface, gl::PreferDiscreteGpu));
+      gl::init::CreateGLContext(nullptr, gl_surface, context_attribs));
   if (!gl_context)
     return false;
 
   gl_context->MakeCurrent(gl_surface);
 
   gpu::gles2::ContextCreationAttribHelper helper;
   config_->GetAttrib(EGL_ALPHA_SIZE, &helper.alpha_size);
   config_->GetAttrib(EGL_DEPTH_SIZE, &helper.depth_size);
   config_->GetAttrib(EGL_STENCIL_SIZE, &helper.stencil_size);
 
@@ skipping 100 matching lines @@
     return false;
   if (!gl_context_->MakeCurrent(gl_surface)) {
     MarkServiceContextLost();
     return false;
   }
   client_gl_context_->Flush();
   return true;
 }
 
 }  // namespace egl