Rename fpdf_edit_create.cpp to cpdf_creator.cpp

This Cl renames the fpdf_edit_create file to better match the
cpdf_creator content. The CPDF_ObjectStream and CPDF_XRefStream code is
moved out to their own .cpp files. Needed anonymous classes are split
out as well.

Change-Id: Ic83fb319ce28c816db82a4286e22032dc68811bc
Reviewed-on: https://pdfium-review.googlesource.com/5171
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index adf318e..a1e487f 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -435,12 +435,18 @@
     "core/fpdfapi/cpdf_modulemgr.h",
     "core/fpdfapi/cpdf_pagerendercontext.cpp",
     "core/fpdfapi/cpdf_pagerendercontext.h",
+    "core/fpdfapi/edit/cpdf_creator.cpp",
     "core/fpdfapi/edit/cpdf_creator.h",
+    "core/fpdfapi/edit/cpdf_encryptor.cpp",
+    "core/fpdfapi/edit/cpdf_encryptor.h",
+    "core/fpdfapi/edit/cpdf_flateencoder.cpp",
+    "core/fpdfapi/edit/cpdf_flateencoder.h",
+    "core/fpdfapi/edit/cpdf_objectstream.cpp",
     "core/fpdfapi/edit/cpdf_objectstream.h",
     "core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp",
     "core/fpdfapi/edit/cpdf_pagecontentgenerator.h",
+    "core/fpdfapi/edit/cpdf_xrefstream.cpp",
     "core/fpdfapi/edit/cpdf_xrefstream.h",
-    "core/fpdfapi/edit/fpdf_edit_create.cpp",
     "core/fpdfapi/font/cpdf_cidfont.cpp",
     "core/fpdfapi/font/cpdf_cidfont.h",
     "core/fpdfapi/font/cpdf_font.cpp",