Bug 771833: Assign an nsIPrincipal to media streams returned by gUM; r=roc

dom/media/MediaManager.cpp

@@ -112,6 +112,13 @@ public:
     // Create a media stream.
     nsCOMPtr<nsDOMMediaStream> stream = nsDOMMediaStream::CreateInputStream();
 
+    nsPIDOMWindow *window = static_cast<nsPIDOMWindow*>
+      (nsGlobalWindow::GetOuterWindowWithId(mWindowID));
+
+    if (window && window->GetExtantDoc()) {
+      stream->CombineWithPrincipal(window->GetExtantDoc()->NodePrincipal());
+    }
+
     // Add our listener. We'll call Start() on the source when get a callback
     // that the MediaStream has started consuming. The listener is freed
     // when the page is invalidated (on navigation or close).
@@ -350,7 +357,7 @@ MediaManager::GetUserMedia(nsPIDOMWindow* aWindow, nsIMediaStreamOptions* aParam
 
   nsresult rv = aParams->GetPicture(&picture);
   NS_ENSURE_SUCCESS(rv, rv);
-  
+
   /**
    * If we were asked to get a picture, before getting a snapshot, we check if
    * the calling page is allowed to open a popup. We do this because

dom/media/MediaManager.h

@@ -6,6 +6,7 @@
 #include "mozilla/Services.h"
 
 #include "nsHashKeys.h"
+#include "nsGlobalWindow.h"
 #include "nsClassHashtable.h"
 #include "nsObserverService.h"