Close all active PeerConnections upon OS suspend

content/browser/renderer_host/media/peer_connection_tracker_host.cc

Index: content/browser/renderer_host/media/peer_connection_tracker_host.cc
diff --git a/content/browser/renderer_host/media/peer_connection_tracker_host.cc b/content/browser/renderer_host/media/peer_connection_tracker_host.cc
index ac863e7eb898e825ed504abcb11b8dc7a83adb9a..7dcc9334ce735499ff2728a522358355917946f4 100644
--- a/content/browser/renderer_host/media/peer_connection_tracker_host.cc
+++ b/content/browser/renderer_host/media/peer_connection_tracker_host.cc
@@ -3,14 +3,20 @@
 // found in the LICENSE file.
 #include "content/browser/renderer_host/media/peer_connection_tracker_host.h"
 
+#include "base/power_monitor/power_monitor.h"
 #include "content/browser/media/webrtc_internals.h"
 #include "content/common/media/peer_connection_tracker_messages.h"
+#include "content/public/browser/render_process_host.h"
 
 namespace content {
 
 PeerConnectionTrackerHost::PeerConnectionTrackerHost(int render_process_id)
     : BrowserMessageFilter(PeerConnectionTrackerMsgStart),
-      render_process_id_(render_process_id) {}
+      render_process_id_(render_process_id) {
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  if (power_monitor)
+    power_monitor->AddObserver(this);
+}
 
 bool PeerConnectionTrackerHost::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
@@ -35,7 +41,17 @@ void PeerConnectionTrackerHost::OverrideThreadForMessage(
     *thread = BrowserThread::UI;
 }
 
+void PeerConnectionTrackerHost::OnSuspend() {

[nasko, 2014/08/15 19:14:19]

nit: I'd move this below with the rest of the methods that deal with IPCs. 

[vrk (LEFT CHROMIUM), 2014/08/15 23:35:25]

Done.

+  content::RenderProcessHost* host =
+      content::RenderProcessHost::FromID(render_process_id_);
+  if (host)

[nasko, 2014/08/15 19:14:18]

This object is created and owned by RenderProcessHost, right? Is there a case
where host will be NULL? If not, it is better to use CHECK(host) to ensure this
is never violated.

[vrk (LEFT CHROMIUM), 2014/08/15 23:35:26]

Good point, Done.

+    host->Send(new PeerConnectionTracker_OnSuspend());
+}
+
 PeerConnectionTrackerHost::~PeerConnectionTrackerHost() {
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  if (power_monitor)
+    power_monitor->RemoveObserver(this);
 }
 
 void PeerConnectionTrackerHost::OnAddPeerConnection(