Impl mus::mojom::GpuService to enable using Chrome IPC version gpu CmdBuf in mus

components/mus/public/cpp/lib/gles2_context.cc

 // Copyright 2014 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/mus/public/cpp/gles2_context.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <utility>
 
+#include "components/mus/public/cpp/lib/command_buffer_client_impl.h"
+#include "components/mus/public/cpp/lib/gpu_service.h"
+#include "components/mus/public/interfaces/command_buffer.mojom.h"
+#include "components/mus/public/interfaces/gpu_service.mojom.h"
 #include "gpu/command_buffer/client/gles2_cmd_helper.h"
-#include "gpu/command_buffer/client/gles2_implementation.h"
 #include "gpu/command_buffer/client/shared_memory_limits.h"
 #include "gpu/command_buffer/client/transfer_buffer.h"
+#include "gpu/ipc/client/command_buffer_proxy_impl.h"
 #include "mojo/public/cpp/system/core.h"
+#include "services/shell/public/cpp/connector.h"
+#include "url/gurl.h"
 
 namespace mus {
 
-GLES2Context::GLES2Context(const std::vector<int32_t>& attribs,
-                           mus::mojom::CommandBufferPtr command_buffer_ptr)
-    : command_buffer_(attribs, std::move(command_buffer_ptr)) {}
+GLES2Context::GLES2Context() {}
 
 GLES2Context::~GLES2Context() {}
 
-bool GLES2Context::Initialize() {
-  if (!command_buffer_.Initialize())
-    return false;
+bool GLES2Context::Initialize(const std::vector<int32_t>& attribs,
+                              shell::Connector* connector) {
+  gpu::CommandBuffer* command_buffer = nullptr;
+  gpu::GpuControl* gpu_control = nullptr;
+  // TODO(penghuang): Use type gpu::gles2::ContextCreationAttribHelper for
+  // attribs.
+  if (!mus::GpuService::UseChromeGpuCommandBuffer()) {
+    mojom::GpuPtr gpu;
+    connector->ConnectToInterface("mojo:mus", &gpu);
+    mojom::CommandBufferPtr command_buffer_ptr;
+    gpu->CreateOffscreenGLES2Context(GetProxy(&command_buffer_ptr));
+    command_buffer_client_impl_.reset(
+        new CommandBufferClientImpl(attribs, std::move(command_buffer_ptr)));
+    if (!command_buffer_client_impl_->Initialize())
+      return false;
+    command_buffer = command_buffer_client_impl_.get();
+    gpu_control = command_buffer_client_impl_.get();
+  } else {
+    scoped_refptr<gpu::GpuChannelHost> gpu_channel_host =
+        GpuService::GetInstance()->EstablishGpuChannel(connector);

[piman, 2016/05/31 23:14:05]

gpu_channel_host can be null, in which case you want to return failure.

[Peng, 2016/06/01 14:11:28]

Done.

+    gpu::SurfaceHandle surface_handle = gfx::kNullAcceleratedWidget;
+    // TODO(penghuang): support shared group.
+    gpu::CommandBufferProxyImpl* shared_command_buffer = nullptr;
+    gpu::GpuStreamId stream_id = gpu::GpuStreamId::GPU_STREAM_DEFAULT;
+    gpu::GpuStreamPriority stream_priority = gpu::GpuStreamPriority::NORMAL;
+    gl::GpuPreference gpu_preference = gl::PreferIntegratedGpu;
+    gpu::gles2::ContextCreationAttribHelper attributes;
+    // TODO(penghuang): figure a useful active_url.
+    GURL active_url;
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner =
+        base::ThreadTaskRunnerHandle::Get();
+    if (!attributes.Parse(attribs))
+      return false;
+    command_buffer_proxy_impl_ = gpu::CommandBufferProxyImpl::Create(
+        std::move(gpu_channel_host), surface_handle, gfx::Size(),
+        shared_command_buffer, stream_id, stream_priority, attributes,
+        active_url, gpu_preference, std::move(task_runner));
+    if (!command_buffer_proxy_impl_)
+      return false;
+    command_buffer = command_buffer_proxy_impl_.get();
+    gpu_control = command_buffer_proxy_impl_.get();
+  }
 
   constexpr gpu::SharedMemoryLimits default_limits;
-  gles2_helper_.reset(new gpu::gles2::GLES2CmdHelper(&command_buffer_));
+  gles2_helper_.reset(new gpu::gles2::GLES2CmdHelper(command_buffer));
   if (!gles2_helper_->Initialize(default_limits.command_buffer_size))
     return false;
   gles2_helper_->SetAutomaticFlushes(false);
   transfer_buffer_.reset(new gpu::TransferBuffer(gles2_helper_.get()));
-  gpu::Capabilities capabilities = command_buffer_.GetCapabilities();
+  gpu::Capabilities capabilities = gpu_control->GetCapabilities();
   bool bind_generates_resource =
       !!capabilities.bind_generates_resource_chromium;
   // TODO(piman): Some contexts (such as compositor) want this to be true, so
   // this needs to be a public parameter.
   bool lose_context_when_out_of_memory = false;
   bool support_client_side_arrays = false;
   implementation_.reset(new gpu::gles2::GLES2Implementation(
       gles2_helper_.get(), NULL, transfer_buffer_.get(),
       bind_generates_resource, lose_context_when_out_of_memory,
-      support_client_side_arrays, &command_buffer_));
+      support_client_side_arrays, gpu_control));
   if (!implementation_->Initialize(default_limits.start_transfer_buffer_size,
                                    default_limits.min_transfer_buffer_size,
                                    default_limits.max_transfer_buffer_size,
                                    default_limits.mapped_memory_reclaim_limit))
     return false;
   return true;
 }
 
+// static
+std::unique_ptr<GLES2Context> GLES2Context::CreateOffscreenContext(
+    const std::vector<int32_t>& attribs,
+    shell::Connector* connector) {
+  std::unique_ptr<GLES2Context> gles2_context(new GLES2Context);
+  if (!gles2_context->Initialize(attribs, connector))
+    gles2_context.reset();
+  return gles2_context;
+}
+
 }  // namespace mus