Rename hw to displayDevice for consistency

Change-Id: I8bdb9be9c0e024d74a5aacc1f78c553cc1bc5ab4
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 3af1754..49964ec 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -405,14 +405,14 @@
     void setUpHWComposer();
     void doComposition();
     void doDebugFlashRegions();
-    void doDisplayComposition(const sp<const DisplayDevice>& hw, const Region& dirtyRegion);
+    void doDisplayComposition(const sp<const DisplayDevice>& displayDevice, const Region& dirtyRegion);
 
     // compose surfaces for display hw. this fails if using GL and the surface
     // has been destroyed and is no longer valid.
-    bool doComposeSurfaces(const sp<const DisplayDevice>& hw, const Region& dirty);
+    bool doComposeSurfaces(const sp<const DisplayDevice>& displayDevice, const Region& dirty);
 
     void postFramebuffer();
-    void drawWormhole(const sp<const DisplayDevice>& hw, const Region& region) const;
+    void drawWormhole(const sp<const DisplayDevice>& displayDevice, const Region& region) const;
 
     /* ------------------------------------------------------------------------
      * Display management