Impose PowerSaveBlock while remoting content via Cast or WebRTC.

chrome/browser/media/cast_transport_host_filter.h

Index: chrome/browser/media/cast_transport_host_filter.h
diff --git a/chrome/browser/media/cast_transport_host_filter.h b/chrome/browser/media/cast_transport_host_filter.h
index 2fd8450e6a0807187142ec898ef969633b6be8b0..147d0a18d16d7320c0e0848921a9e02c0fab8d47 100644
--- a/chrome/browser/media/cast_transport_host_filter.h
+++ b/chrome/browser/media/cast_transport_host_filter.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_MEDIA_CAST_TRANSPORT_HOST_FILTER_H_
 
 #include "base/id_map.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/default_tick_clock.h"
 #include "chrome/common/cast_messages.h"
@@ -14,6 +15,10 @@
 #include "media/cast/logging/logging_defines.h"
 #include "media/cast/net/cast_transport_sender.h"
 
+namespace content {
+class PowerSaveBlocker;
+}  // namespace content
+
 namespace cast {
 
 class CastTransportHostFilter : public content::BrowserMessageFilter {
@@ -76,6 +81,11 @@ class CastTransportHostFilter : public content::BrowserMessageFilter {
   // Clock used by Cast transport.
   base::DefaultTickClock clock_;
 
+  // While |id_map_| is non-empty, hold an instance of
+  // content::PowerSaveBlocker.  This prevents Chrome from being suspended while
+  // remoting content.
+  scoped_ptr<content::PowerSaveBlocker> power_save_blocker_;
+
   base::WeakPtrFactory<CastTransportHostFilter> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CastTransportHostFilter);