SurfaceFlinger: add support for secure displays

This change adds support for displays that are not allowed to display surfaces
with the eSecure flag set.  All non-virtual displays are considered secure,
while virtual displays have their secure-ness specified at creation time.

Bug: 7368436
Change-Id: I81ad535d2d1e5a7ff78269017e85b111f0098500
diff --git a/include/ui/DisplayInfo.h b/include/ui/DisplayInfo.h
index c7dc354..c3a4d6b 100644
--- a/include/ui/DisplayInfo.h
+++ b/include/ui/DisplayInfo.h
@@ -32,7 +32,8 @@
     float fps;
     float density;
     uint8_t orientation;
-    uint8_t reserved[3];
+    bool secure;
+    uint8_t reserved[2];
     // TODO: this needs to go away (currently needed only by webkit)
     PixelFormatInfo pixelFormatInfo;
 };