Sync "restrained media controller" with the spec

Source/core/html/MediaController.cpp

Index: Source/core/html/MediaController.cpp
diff --git a/Source/core/html/MediaController.cpp b/Source/core/html/MediaController.cpp
index f86a22a81cd59863f3314c1aeb8b3cd4005845c5..0a72d6f3fe1934fbde326f01e91e2a93ae96245e 100644
--- a/Source/core/html/MediaController.cpp
+++ b/Source/core/html/MediaController.cpp
@@ -503,10 +503,6 @@ bool MediaController::isRestrained() const
     for (MediaElementSequence::const_iterator it = m_mediaElements.begin(); it != m_mediaElements.end(); ++it) {
         HTMLMediaElement* element = *it;
 
-        // and none of its slaved media elements are blocked media elements,
-        if (element->isBlocked())
-            return false;
-
         if (element->isAutoplaying() && element->paused())
             anyAutoplayingAndPaused = true;