Update Android's FontHost to return NULL if familyName does not match

src/ports/SkFontConfigInterface_android.cpp

Index: src/ports/SkFontConfigInterface_android.cpp
diff --git a/src/ports/SkFontConfigInterface_android.cpp b/src/ports/SkFontConfigInterface_android.cpp
index 9a38261e80262789788e545dd9d86cbb5d1d9825..f56308dda94fab7624599ee5f767e5ac710158fd 100644
--- a/src/ports/SkFontConfigInterface_android.cpp
+++ b/src/ports/SkFontConfigInterface_android.cpp
@@ -413,10 +413,11 @@ bool SkFontConfigInterfaceAndroid::matchFamilyName(const char familyName[],
 
     }
 
+    // If no matching family name is found then return false. This allows clients
+    // to be able to search for other fonts instead of forcing them to use the
+    // default font.
     if (INVALID_FAMILY_REC_ID == familyRecID) {
-        //TODO this ensures that we always return something
-        familyRecID = fDefaultFamilyRecID;
-        //return false;
+        return false;
     }
 
     FontRecID fontRecID = find_best_style(fFontFamilies[familyRecID], style);