SurfacelessSurfaces for Mus

components/mus/surfaces/surfaces_context_provider.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/surfaces/surfaces_context_provider.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 18 matching lines @@
 
 SurfacesContextProvider::SurfacesContextProvider(
     SurfacesContextProviderDelegate* delegate,
     gfx::AcceleratedWidget widget,
     const scoped_refptr<GpuState>& state)
     : delegate_(delegate), widget_(widget), command_buffer_local_(nullptr) {
   capabilities_.gpu.image = true;
   command_buffer_local_ = new CommandBufferLocal(this, widget_, state);
 }
 
+// This routine needs to be safe to call more than once.
 // This is called when we have an accelerated widget.
 bool SurfacesContextProvider::BindToCurrentThread() {
+  if (implementation_)
+    return true;
+
   // SurfacesContextProvider should always live on the same thread as the
   // Window Manager.
   DCHECK(CalledOnValidThread());
   if (!command_buffer_local_->Initialize())
     return false;
   gles2_helper_.reset(
       new gpu::gles2::GLES2CmdHelper(command_buffer_local_));
   if (!gles2_helper_->Initialize(kDefaultCommandBufferSize))
     return false;
   gles2_helper_->SetAutomaticFlushes(false);
   transfer_buffer_.reset(new gpu::TransferBuffer(gles2_helper_.get()));
   capabilities_.gpu = command_buffer_local_->GetCapabilities();
   bool bind_generates_resource =
       !!capabilities_.gpu.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_local_));
   return implementation_->Initialize(
       kDefaultStartTransferBufferSize, kDefaultMinTransferBufferSize,
       kDefaultMaxTransferBufferSize, gpu::gles2::GLES2Implementation::kNoLimit);
 }
 
 gpu::gles2::GLES2Interface* SurfacesContextProvider::ContextGL() {
+  DCHECK(implementation_);
   return implementation_.get();
 }
 
 gpu::ContextSupport* SurfacesContextProvider::ContextSupport() {
   return implementation_.get();
 }
 
 class GrContext* SurfacesContextProvider::GrContext() {
   return NULL;
 }
@@ skipping 40 matching lines @@
     swap_buffers_completion_callback_.Run(result);
   }
 }
 
 void SurfacesContextProvider::SetSwapBuffersCompletionCallback(
     gfx::GLSurface::SwapCompletionCallback callback) {
   swap_buffers_completion_callback_ = callback;
 }
 
 }  // namespace mus