Add metrics for usage of permission features from iframes in blink

third_party/WebKit/Source/modules/mediastream/UserMediaRequest.cpp

 /*
  * Copyright (C) 2011 Ericsson AB. All rights reserved.
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 107 matching lines @@
 {
     return m_video;
 }
 
 bool UserMediaRequest::isSecureContextUse(String& errorMessage)
 {
     Document* document = ownerDocument();
 
     if (document->isSecureContext(errorMessage)) {
         UseCounter::count(document->frame(), UseCounter::GetUserMediaSecureOrigin);
+        UseCounter::countCrossOriginIframe(*document, UseCounter::GetUserMediaSecureOriginIframe);

[mlamouri (slow - plz ping), 2016/01/19 17:54:48]

Should you add a GetUserMediaInsecureOriginIframe like you did for Geolocation?

[raymes, 2016/01/20 00:13:12]

It's not very useful (for us at least) because it no longer works on http on
ToT. If you're interested I can add it as well.

[mlamouri (slow - plz ping), 2016/01/21 13:53:18]

You do it for geolocation. I think you should do it for gUM unless we have a
good reason not to.

[raymes, 2016/01/27 06:57:51]

Done.

         OriginsUsingFeatures::countAnyWorld(*document, OriginsUsingFeatures::Feature::GetUserMediaSecureOrigin);
         return true;
     }
 
     // While getUserMedia is blocked on insecure origins, we still want to
     // count attempts to use it.
     UseCounter::countDeprecation(document->frame(), UseCounter::GetUserMediaInsecureOrigin);
     OriginsUsingFeatures::countAnyWorld(*document, OriginsUsingFeatures::Feature::GetUserMediaInsecureOrigin);
     return false;
 }
@@ skipping 68 matching lines @@
 
 DEFINE_TRACE(UserMediaRequest)
 {
     visitor->trace(m_controller);
     visitor->trace(m_successCallback);
     visitor->trace(m_errorCallback);
     ContextLifecycleObserver::trace(visitor);
 }
 
 } // namespace blink