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

chrome/browser/media/media_stream_devices_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/media/media_stream_devices_controller.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
@@ skipping 327 matching lines @@
 
     // TODO(raymes): We currently set the content permission for non-https
     // websites for Pepper requests as well. This is temporary and should be
     // removed.
     if (update_content_setting) {
       if ((IsSchemeSecure() && !devices.empty()) ||
           request_.request_type == content::MEDIA_OPEN_DEVICE) {
         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;
   if (!devices.empty()) {
     ui = MediaCaptureDevicesDispatcher::GetInstance()->
         GetMediaStreamCaptureIndicator()->RegisterMediaStream(
             web_contents_, devices);
   }
   content::MediaResponseCallback cb = callback_;
   callback_.Reset();
@@ skipping 295 matching lines @@
           it->second.permission == MEDIA_ALLOWED);
 }
 
 bool MediaStreamDevicesController::IsDeviceVideoCaptureRequestedAndAllowed()
     const {
   MediaStreamTypeSettingsMap::const_iterator it =
       request_permissions_.find(content::MEDIA_DEVICE_VIDEO_CAPTURE);
   return (it != request_permissions_.end() &&
           it->second.permission == MEDIA_ALLOWED);
 }