workaround to set the WM refresh rate to 48 Hz for tuna devices only

this is TEMPORARY until we can do this properly.

Bug: 5572464
Change-Id: I6537706d636a83a4a50e2900d6b829dd89b6f245
diff --git a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
index f4be168..329c052 100644
--- a/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
+++ b/services/surfaceflinger/DisplayHardware/DisplayHardware.cpp
@@ -141,6 +141,17 @@
     mDpiY = mNativeWindow->ydpi;
     mRefreshRate = fbDev->fps;
 
+
+/* FIXME: this is a temporary HACK until we are able to report the refresh rate
+ * properly from the HAL. The WindowManagerService now relies on this value.
+ */
+#ifndef REFRESH_RATE
+    mRefreshRate = fbDev->fps;
+#else
+    mRefreshRate = REFRESH_RATE;
+#warning "refresh rate set via makefile to REFRESH_RATE"
+#endif
+
     EGLint w, h, dummy;
     EGLint numConfigs=0;
     EGLSurface surface;