Rename fpdf_render_image and fpdf_render_text

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 4125d0f11b6bc6332e986116ab7a5f4f1b556309..bf28674c4f901afd11005c4137206a99cbcc4729 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -543,6 +543,8 @@ static_library("fpdfapi") {
     "core/fpdfapi/render/cpdf_charposlist.h",
     "core/fpdfapi/render/cpdf_devicebuffer.cpp",
     "core/fpdfapi/render/cpdf_devicebuffer.h",
+    "core/fpdfapi/render/cpdf_dibtransferfunc.cpp",
+    "core/fpdfapi/render/cpdf_dibtransferfunc.h",
     "core/fpdfapi/render/cpdf_docrenderdata.cpp",
     "core/fpdfapi/render/cpdf_docrenderdata.h",
     "core/fpdfapi/render/cpdf_imagecacheentry.cpp",
@@ -563,6 +565,7 @@ static_library("fpdfapi") {
     "core/fpdfapi/render/cpdf_renderstatus.h",
     "core/fpdfapi/render/cpdf_scaledrenderbuffer.cpp",
     "core/fpdfapi/render/cpdf_scaledrenderbuffer.h",
+    "core/fpdfapi/render/cpdf_textrenderer.cpp",
     "core/fpdfapi/render/cpdf_textrenderer.h",
     "core/fpdfapi/render/cpdf_transferfunc.cpp",
     "core/fpdfapi/render/cpdf_transferfunc.h",
@@ -570,9 +573,7 @@ static_library("fpdfapi") {
     "core/fpdfapi/render/cpdf_type3cache.h",
     "core/fpdfapi/render/cpdf_type3glyphs.cpp",
     "core/fpdfapi/render/cpdf_type3glyphs.h",
-    "core/fpdfapi/render/fpdf_render_image.cpp",
     "core/fpdfapi/render/fpdf_render_loadimage.cpp",
-    "core/fpdfapi/render/fpdf_render_text.cpp",
     "core/fpdfapi/render/render_int.h",
   ]
   configs += [ ":pdfium_core_config" ]