command_buffer: Add support for creating non-WebGL ES 3 contexts

components/html_viewer/web_graphics_context_3d_command_buffer_impl.cc

 // Copyright 2015 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 "components/html_viewer/web_graphics_context_3d_command_buffer_impl.h"
 
 #include "components/mus/public/interfaces/gpu.mojom.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "mojo/application/public/cpp/application_impl.h"
 #include "mojo/cc/context_provider_mojo.h"
@@ skipping 14 matching lines @@
   mojo::GpuPtr gpu_service;
   app->ConnectToService(request.Pass(), &gpu_service);
 
   mojo::CommandBufferPtr cb;
   gpu_service->CreateOffscreenGLES2Context(GetProxy(&cb));
   command_buffer_handle_ = cb.PassInterface().PassHandle();
   CHECK(command_buffer_handle_.is_valid());
   // TODO(penghuang): Support share context.
   // TODO(penghuang): Fill gl_info.
   gpu::gles2::ContextCreationAttribHelper attrib_helper;
-  attrib_helper.alpha_size = attributes.alpha ? 8 : 0;
-  attrib_helper.depth_size = attributes.depth ? 24 : 0;
-  attrib_helper.stencil_size = attributes.stencil ? 8 : 0;
-  attrib_helper.samples = attributes.antialias ? 4 : 0;
-  attrib_helper.sample_buffers = attributes.antialias ? 1 : 0;
-  attrib_helper.fail_if_major_perf_caveat =
-      attributes.failIfMajorPerformanceCaveat;
-  attrib_helper.bind_generates_resource = false;
-  attrib_helper.webgl_version = attributes.webGLVersion;
+  ConvertAttributes(attributes, &attrib_helper);
   std::vector<int32_t> attrib_vector;
   attrib_helper.Serialize(&attrib_vector);
   gles2_context_ = MojoGLES2CreateContext(
       command_buffer_handle_.release().value(),
       attrib_vector.data(),
       &ContextLostThunk,
       this,
       mojo::Environment::GetDefaultAsyncWaiter());
   context_gl_.reset(new mojo::MojoGLES2Impl(gles2_context_));
   setGLInterface(context_gl_.get());
@@ skipping 16 matching lines @@
   return new WebGraphicsContext3DCommandBufferImpl(
       app, active_url, attributes, share_context, gl_info);
 }
 
 void WebGraphicsContext3DCommandBufferImpl::ContextLost() {
   if (context_lost_callback_)
     context_lost_callback_->onContextLost();
 }
 
 }  // namespace html_viewer