Use PowerSaveBlocker for audio and video on Chrome OS.

chrome/browser/apps/ephemeral_app_browsertest.cc

Index: chrome/browser/apps/ephemeral_app_browsertest.cc
diff --git a/chrome/browser/apps/ephemeral_app_browsertest.cc b/chrome/browser/apps/ephemeral_app_browsertest.cc
index da8e8bf149b4e3f34e4f682d161edfae99452805..04c96fe60c3ef0a717c286ab786af91e4d38757f 100644
--- a/chrome/browser/apps/ephemeral_app_browsertest.cc
+++ b/chrome/browser/apps/ephemeral_app_browsertest.cc
@@ -160,7 +160,8 @@ class PowerSaveBlockerStub : public content::PowerSaveBlocker {
 
   static scoped_ptr<PowerSaveBlocker> Create(PowerSettingsMock* power_settings,
                                              PowerSaveBlockerType type,
-                                             const std::string& reason) {
+                                             Reason reason,
+                                             const std::string& description) {
     return scoped_ptr<PowerSaveBlocker>(
         new PowerSaveBlockerStub(power_settings));
   }