Request context sharing via content::ContextProviderCommandBuffer

gpu/command_buffer/client/gles2_implementation.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.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
@@ skipping 93 matching lines @@
   ++gles2_implementation_->use_count_;
 }
 
 GLES2Implementation::SingleThreadChecker::~SingleThreadChecker() {
   --gles2_implementation_->use_count_;
   CHECK_EQ(0, gles2_implementation_->use_count_);
 }
 
 GLES2Implementation::GLES2Implementation(
     GLES2CmdHelper* helper,
-    ShareGroup* share_group,
+    scoped_refptr<ShareGroup> share_group,
     TransferBufferInterface* transfer_buffer,
     bool bind_generates_resource,
     bool lose_context_when_out_of_memory,
     bool support_client_side_arrays,
     GpuControl* gpu_control)
     : helper_(helper),
       transfer_buffer_(transfer_buffer),
       chromium_framebuffer_multisample_(kUnknownExtensionStatus),
       pack_alignment_(4),
       pack_row_length_(0),
@@ skipping 54 matching lines @@
     debug_ = base::CommandLine::ForCurrentProcess()->HasSwitch(
         switches::kEnableGPUClientLogging);
   });
 
   share_group_ =
       (share_group ? share_group
                    : new ShareGroup(
                          bind_generates_resource,
                          gpu_control_->GetCommandBufferID().GetUnsafeValue()));
   DCHECK(share_group_->bind_generates_resource() == bind_generates_resource);
+  DCHECK(!share_group_->IsLost());

[piman, 2016/04/27 22:09:33]

I don't think we want this DCHECK - another thread may have lost the share group
after it's passed to the constructor. The GLES2Implementation maybe DOA, but
such is life?

[danakj, 2016/04/28 00:25:58]

Ah.. ya fair point. Removed and moved the check to IsLost in the context
provider to be *after* the GLES2Impl is set up.

 
   memset(&reserved_ids_, 0, sizeof(reserved_ids_));
 }
 
 bool GLES2Implementation::Initialize(
     unsigned int starting_transfer_buffer_size,
     unsigned int min_transfer_buffer_size,
     unsigned int max_transfer_buffer_size,
     unsigned int mapped_memory_limit) {
   TRACE_EVENT0("gpu", "GLES2Implementation::Initialize");
@@ skipping 6611 matching lines @@
   cached_extensions_.clear();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu