Created multi-process-friendly PowerMonitor interface.

content/gpu/gpu_main.cc

Index: content/gpu/gpu_main.cc
diff --git a/content/gpu/gpu_main.cc b/content/gpu/gpu_main.cc
index 22a8bf30711b79a6288e504c054d8ae522174137..db61560bba275af99f4da41d334c024bb287daa6 100644
--- a/content/gpu/gpu_main.cc
+++ b/content/gpu/gpu_main.cc
@@ -11,6 +11,7 @@
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
 #include "base/message_loop.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/rand_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
@@ -20,6 +21,7 @@
 #include "content/common/content_constants_internal.h"
 #include "content/common/gpu/gpu_config.h"
 #include "content/common/gpu/gpu_messages.h"
+#include "content/common/power_monitor_broadcast_source.h"
 #include "content/common/sandbox_linux.h"
 #include "content/gpu/gpu_child_thread.h"
 #include "content/gpu/gpu_process.h"
@@ -173,6 +175,13 @@ int GpuMain(const MainFunctionParams& parameters) {
   delayed_watchdog_enable = true;
 #endif
 
+  scoped_ptr<PowerMonitorBroadcastSource> power_monitor_source(

[jam, 2013/07/17 00:29:42]

this should be connected in all processes (i.e. in ChildProcess or ChildThread)
since you put this class in content/common

+      new PowerMonitorBroadcastSource(main_message_loop.message_loop_proxy()));
+  IPC::ChannelProxy::MessageFilter* power_monitor_message_filter =
+      power_monitor_source->MessageFilter();
+  scoped_ptr<base::PowerMonitor> power_monitor(new base::PowerMonitor(
+      power_monitor_source.PassAs<base::PowerMonitorSource>()));
+
   scoped_refptr<GpuWatchdogThread> watchdog_thread;
 
   // Start the GPU watchdog only after anything that is expected to be time
@@ -287,6 +296,9 @@ int GpuMain(const MainFunctionParams& parameters) {
                                                     dead_on_arrival,
                                                     gpu_info,
                                                     deferred_messages.Get());
+
+  child_thread->channel()->AddFilter(power_monitor_message_filter);
+
   while (!deferred_messages.Get().empty())
     deferred_messages.Get().pop();