Created multi-process-friendly PowerMonitor interface.

content/common/gpu/client/gpu_channel_host.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 "content/common/gpu/client/gpu_channel_host.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/posix/eintr_wrapper.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/common/gpu/client/command_buffer_proxy_impl.h"
 #include "content/common/gpu/gpu_messages.h"
+#include "content/common/power_monitor_service.h"
 #include "googleurl/src/gurl.h"
 #include "gpu/command_buffer/common/mailbox.h"
 #include "ipc/ipc_sync_message_filter.h"
 
 #if defined(OS_WIN)
 #include "content/public/common/sandbox_init.h"
 #endif
 
 using base::AutoLock;
 using base::MessageLoopProxy;
@@ skipping 18 matching lines @@
   return host;
 }
 
 GpuChannelHost::GpuChannelHost(GpuChannelHostFactory* factory,
                                int gpu_host_id,
                                int client_id,
                                const gpu::GPUInfo& gpu_info)
     : factory_(factory),
       client_id_(client_id),
       gpu_host_id_(gpu_host_id),
-      gpu_info_(gpu_info) {
+      gpu_info_(gpu_info),
+      power_monitor_service_(new PowerMonitorService(this)) {
   next_transfer_buffer_id_.GetNext();
+
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  if (power_monitor)
+    power_monitor->AddObserver(power_monitor_service_.get());

[Ken Russell (switch to Gerrit), 2013/06/24 22:54:38]

Unless I'm misremembering and misreading the code, GpuChannelHosts are
instantiated both in the browser process and renderer processes. See
RenderThreadImpl::EstablishGpuChannelSync and
BrowserGpuChannelHostFactory::EstablishGpuChannelSync . Did you run into this
problem and/or expect this? I don't think the renderer process should attempt to
instantiate any power monitor-related objects. If the code deliberately runs
differently in the browser and renderer processes then big comments should be
added to the power_monitor_service_ field in the header pointing out that it's
only used in the browser, and the PowerMontiorService shouldn't even be created
if base::PowerMonitor::Get() returns NULL.

 }
 
 void GpuChannelHost::Connect(const IPC::ChannelHandle& channel_handle) {
   // Open a channel to the GPU process. We pass NULL as the main listener here
   // since we need to filter everything to route it to the right thread.
   scoped_refptr<base::MessageLoopProxy> io_loop = factory_->GetIOLoopProxy();
   channel_.reset(new IPC::SyncChannel(channel_handle,
                                       IPC::Channel::MODE_CLIENT,
                                       NULL,
                                       io_loop.get(),
@@ skipping 329 matching lines @@
   AutoLock lock(lock_);
   DCHECK_LE(names.size(), requested_mailboxes_);
   requested_mailboxes_ -= names.size();
   mailbox_name_pool_.insert(mailbox_name_pool_.end(),
                             names.begin(),
                             names.end());
 }
 
 
 }  // namespace content