Report lost context from GLES2Implementation based on share group state.

ppapi/proxy/ppapi_command_buffer_proxy.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.
 
 #include "ppapi/proxy/ppapi_command_buffer_proxy.h"
 
 #include <utility>
 
 #include "base/numerics/safe_conversions.h"
 #include "ppapi/proxy/ppapi_messages.h"
@@ skipping 161 matching lines @@
     return;
 
   Send(new PpapiHostMsg_PPBGraphics3D_DestroyTransferBuffer(
       ppapi::API_ID_PPB_GRAPHICS_3D, resource_, id));
 }
 
 void PpapiCommandBufferProxy::SetLock(base::Lock*) {
   NOTIMPLEMENTED();
 }
 
-bool PpapiCommandBufferProxy::IsGpuChannelLost() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
 void PpapiCommandBufferProxy::EnsureWorkVisible() {
   DCHECK_GE(flushed_fence_sync_release_, validated_fence_sync_release_);
   Send(new PpapiHostMsg_PPBGraphics3D_EnsureWorkVisible(
       ppapi::API_ID_PPB_GRAPHICS_3D, resource_));
   validated_fence_sync_release_ = flushed_fence_sync_release_;
 }
 
 gpu::CommandBufferNamespace PpapiCommandBufferProxy::GetNamespaceID() const {
   return gpu::CommandBufferNamespace::GPU_IO;
 }
@@ skipping 129 matching lines @@
   message->set_unblock(true);
   Send(message);
 
   flush_info_->flush_pending = false;
   flush_info_->resource.SetHostResource(0, 0);
   flushed_fence_sync_release_ = pending_fence_sync_release_;
 }
 
 }  // namespace proxy
 }  // namespace ppapi