Move Android SkFontMgr::Factory to its own file.

include/ports/SkFontMgr_android.h

Index: include/ports/SkFontMgr_android.h
diff --git a/include/ports/SkFontMgr_android.h b/include/ports/SkFontMgr_android.h
index 8d1cafd2cc7e45f0fc3921996ed5b9cf8dc1dcdc..e489b161b2a602629f6f6a17efeb8b1d9492b5ff 100644
--- a/include/ports/SkFontMgr_android.h
+++ b/include/ports/SkFontMgr_android.h
@@ -12,6 +12,13 @@
 
 class SkFontMgr;
 
+/**
+ *  For test only -- this only affects the default factory.
+ *  Load font config from given xml files, instead of those from Android system.
+ */
+SK_API void SkUseTestFontConfigFile(const char* mainconf, const char* fallbackconf,
+                                    const char* fontsdir);
+
 struct SkFontMgr_Android_CustomFonts {
     /** When specifying custom fonts, indicates how to use system fonts. */
     enum SystemFontUse {