add dummpy SkFontMgr::Factory() impl to font backends, so we can start testing it

trunk/src/ports/SkFontHost_android.cpp

Index: trunk/src/ports/SkFontHost_android.cpp
===================================================================
--- trunk/src/ports/SkFontHost_android.cpp	(revision 8405)
+++ trunk/src/ports/SkFontHost_android.cpp	(working copy)
@@ -1064,3 +1064,12 @@
     SkDEBUGF(("Use Test Config File Main %s, Fallback %s, Font Dir %s",
               gTestMainConfigFile, gTestFallbackConfigFile, gTestFontFilePrefix));
 }
+
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkFontMgr.h"
+
+SkFontMgr* SkFontMgr::Factory() {
+    // todo
+    return NULL;
+}