Eradicate DisplayID.

DisplayDevices are now keyed of the wp<IBinder> the client uses.
DisplayID has now become DisplayType which is just used to identify
physical displays (as opposed to virtual displays such as wifi displays).

Change-Id: I0c5968f2c902dcd699a7e0afacf833ff070c12ea
diff --git a/services/surfaceflinger/LayerBase.h b/services/surfaceflinger/LayerBase.h
index 6394542..c18f397 100644
--- a/services/surfaceflinger/LayerBase.h
+++ b/services/surfaceflinger/LayerBase.h
@@ -54,9 +54,8 @@
     static int32_t sSequence;
 
 public:
-            LayerBase(SurfaceFlinger* flinger, DisplayID display);
+            LayerBase(SurfaceFlinger* flinger);
 
-    DisplayID           dpy;
     mutable bool        contentDirty;
             // regions below are in window-manager space
             Region      visibleRegion;
@@ -293,8 +292,7 @@
 class LayerBaseClient : public LayerBase
 {
 public:
-            LayerBaseClient(SurfaceFlinger* flinger, DisplayID display,
-                        const sp<Client>& client);
+            LayerBaseClient(SurfaceFlinger* flinger, const sp<Client>& client);
 
             virtual ~LayerBaseClient();