Audit the last time the media stream content settings have been used.

chrome/browser/media/media_stream_devices_controller.cc

Index: chrome/browser/media/media_stream_devices_controller.cc
diff --git a/chrome/browser/media/media_stream_devices_controller.cc b/chrome/browser/media/media_stream_devices_controller.cc
index 3cb55cc23313826bef8491fc84a3064ca910a278..1103f9af842553ecfca9291206d657caa8c569f8 100644
--- a/chrome/browser/media/media_stream_devices_controller.cc
+++ b/chrome/browser/media/media_stream_devices_controller.cc
@@ -345,6 +345,19 @@ void MediaStreamDevicesController::Accept(bool update_content_setting) {
         SetPermission(true);
       }
     }
+
+    if (audio_allowed) {
+      profile_->GetHostContentSettingsMap()->UpdateLastUsageByPattern(
+          ContentSettingsPattern::FromURLNoWildcard(request_.security_origin),
+          ContentSettingsPattern::Wildcard(),
+          CONTENT_SETTINGS_TYPE_MEDIASTREAM_MIC);
+    }
+    if (video_allowed) {
+      profile_->GetHostContentSettingsMap()->UpdateLastUsageByPattern(
+          ContentSettingsPattern::FromURLNoWildcard(request_.security_origin),
+          ContentSettingsPattern::Wildcard(),
+          CONTENT_SETTINGS_TYPE_MEDIASTREAM_CAMERA);
+    }
   }
 
   scoped_ptr<content::MediaStreamUI> ui;