SurfaceFlinger: Respect the PROTECTED gralloc bit.

This change makes SurfaceFlinger treat layers for which the active
buffer has the GRALLOC_USAGE_PROTECTED bit set as if they have the
'secure' flag set.

Change-Id: Ic60b6513a63e4bb92ec6ce9fd12fd39b4ba5f674
Bug: 4081304
diff --git a/services/surfaceflinger/LayerBase.h b/services/surfaceflinger/LayerBase.h
index bfe92e6..7162e47 100644
--- a/services/surfaceflinger/LayerBase.h
+++ b/services/surfaceflinger/LayerBase.h
@@ -197,16 +197,10 @@
     virtual bool isSecure() const       { return false; }
 
     /**
-     * isProtectedByApp - true if application says this surface is protected, that
-     * is if it requires a hardware-protected data path to an external sink.
+     * isProtected - true if the layer may contain protected content in the
+     * GRALLOC_USAGE_PROTECTED sense.
      */
-    virtual bool isProtectedByApp() const   { return false; }
-
-    /**
-     * isProtectedByDRM - true if DRM agent says this surface is protected, that
-     * is if it requires a hardware-protected data path to an external sink.
-     */
-    virtual bool isProtectedByDRM() const   { return false; }
+    virtual bool isProtected() const   { return false; }
 
     /** Called from the main thread, when the surface is removed from the
      * draw list */