Remove usage of FOR_EACH_OBSERVER macro in gpu

gpu/ipc/client/command_buffer_proxy_impl.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 "gpu/ipc/client/command_buffer_proxy_impl.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 82 matching lines @@
   std::unique_ptr<CommandBufferProxyImpl> command_buffer = base::WrapUnique(
       new CommandBufferProxyImpl(host->channel_id(), route_id, stream_id));
   if (!command_buffer->Initialize(std::move(host), std::move(init_params),
                                   std::move(task_runner)))
     return nullptr;
 
   return command_buffer;
 }
 
 CommandBufferProxyImpl::~CommandBufferProxyImpl() {
-  FOR_EACH_OBSERVER(DeletionObserver, deletion_observers_, OnWillDeleteImpl());
+  for (auto& observer : deletion_observers_)
+    observer.OnWillDeleteImpl();
   DisconnectChannel();
 }
 
 bool CommandBufferProxyImpl::OnMessageReceived(const IPC::Message& message) {
   std::unique_ptr<base::AutoLock> lock;
   if (lock_)
     lock.reset(new base::AutoLock(*lock_));
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(CommandBufferProxyImpl, message)
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_Destroyed, OnDestroyed);
@@ skipping 751 matching lines @@
     return;
   channel_->FlushPendingStream(stream_id_);
   channel_->Send(new GpuChannelMsg_DestroyCommandBuffer(route_id_));
   channel_->RemoveRoute(route_id_);
   channel_ = nullptr;
   if (gpu_control_client_)
     gpu_control_client_->OnGpuControlLostContext();
 }
 
 }  // namespace gpu