Unify some code

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index a77ea4c6b207dc7b277420a9cc62b4a5e07e5b2a..20403d2a40d0955d5aa03f8da8e1dce87fb4111c 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -500,6 +500,8 @@ static_library("fpdfapi") {
     "core/fpdfapi/parser/cpdf_hint_tables.h",
     "core/fpdfapi/parser/cpdf_indirect_object_holder.cpp",
     "core/fpdfapi/parser/cpdf_indirect_object_holder.h",
+    "core/fpdfapi/parser/cpdf_linearized.cpp",
+    "core/fpdfapi/parser/cpdf_linearized.h",
     "core/fpdfapi/parser/cpdf_name.cpp",
     "core/fpdfapi/parser/cpdf_name.h",
     "core/fpdfapi/parser/cpdf_null.cpp",