Fix for bug 3477330

This patch fixs a crash bug caused by using a NULL DecryptHandle pointer in the DRM Framework.
Fix by using sp<DecryptHandle> instead.

Change-Id: I1355d4719857ab64ad6cd12803fcf19e45bb50a0

proprietary/wvm/WVMMediaSource.cpp

@@ -19,6 +19,7 @@
 
 #include "WVMMediaSource.h"
 #include "WVMFileSource.h"
+#include "WVMExtractorImpl.h"
 #include "media/stagefright/MediaErrors.h"
 #include "media/stagefright/MediaDefs.h"
 #include "media/stagefright/MediaDebug.h"
@@ -274,8 +275,10 @@ WVMMediaSource::~WVMMediaSource()
     }
 
     if (mESSelector == WV_EsSelector_Video) {
-        if (mSession != NULL)
+        if (mSession != NULL) {
             WV_Teardown(mSession);
+        }
+        WVMExtractorImpl::cleanup();
     }
 }