Pass display arg to blank/unblank

This allows us to blank and unblank displays other than the built-in
display (e.g. HDMI).

Bug: 7240511
Change-Id: I89ea13f9e497be74c3e1231d0c62fb558e93e0f8
diff --git a/include/gui/ISurfaceComposer.h b/include/gui/ISurfaceComposer.h
index a20caf9..5d2d8d7 100644
--- a/include/gui/ISurfaceComposer.h
+++ b/include/gui/ISurfaceComposer.h
@@ -99,10 +99,10 @@
 
 
     /* triggers screen off and waits for it to complete */
-    virtual void blank() = 0;
+    virtual void blank(const sp<IBinder>& display) = 0;
 
     /* triggers screen on and waits for it to complete */
-    virtual void unblank() = 0;
+    virtual void unblank(const sp<IBinder>& display) = 0;
 
     /* returns information about a display
      * intended to be used to get information about built-in displays */