Rename some fsdk files to cpdfsdk

This CL renames fsdk_common and fsdk_define to cpdfsdk_common and
cpdfsdk_helpers respectively.

Change-Id: I8ee7a308561f1ff2f510954444f953b0c8fed788
Reviewed-on: https://pdfium-review.googlesource.com/29371
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>
diff --git a/fpdfsdk/fpdfdoc.cpp b/fpdfsdk/fpdfdoc.cpp
index 2ba0053..d8be120 100644
--- a/fpdfsdk/fpdfdoc.cpp
+++ b/fpdfsdk/fpdfdoc.cpp
@@ -16,7 +16,7 @@
 #include "core/fpdfdoc/cpdf_bookmarktree.h"
 #include "core/fpdfdoc/cpdf_dest.h"
 #include "core/fpdfdoc/cpdf_pagelabel.h"
-#include "fpdfsdk/fsdk_define.h"
+#include "fpdfsdk/cpdfsdk_helpers.h"
 #include "third_party/base/ptr_util.h"
 #include "third_party/base/stl_util.h"