Move CPDF_DocRenderData from render_int

First CL in an attempt to reduce the class cluttering in
fpdf_render_text, fpdf_render_image, and fpdf_render.

Review-Url: https://codereview.chromium.org/2507023006
diff --git a/BUILD.gn b/BUILD.gn
index f04ec48..f91ea0e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -534,6 +534,8 @@
     "core/fpdfapi/parser/fpdf_parser_decode.h",
     "core/fpdfapi/parser/fpdf_parser_utility.cpp",
     "core/fpdfapi/parser/fpdf_parser_utility.h",
+    "core/fpdfapi/render/cpdf_docrenderdata.cpp",
+    "core/fpdfapi/render/cpdf_docrenderdata.h",
     "core/fpdfapi/render/cpdf_pagerendercache.h",
     "core/fpdfapi/render/cpdf_progressiverenderer.h",
     "core/fpdfapi/render/cpdf_rendercontext.h",