Move core/fpdfapi/fpdf_page to core/fpdfapi/page

BUG=pdfium:603

Review-Url: https://codereview.chromium.org/2386423004
diff --git a/fpdfsdk/fpdfdoc.cpp b/fpdfsdk/fpdfdoc.cpp
index 7abeca3..639fed9 100644
--- a/fpdfsdk/fpdfdoc.cpp
+++ b/fpdfsdk/fpdfdoc.cpp
@@ -8,9 +8,9 @@
 
 #include <set>
 
-#include "core/fpdfapi/fpdf_page/cpdf_page.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_array.h"
 #include "core/fpdfapi/fpdf_parser/cpdf_document.h"
+#include "core/fpdfapi/page/cpdf_page.h"
 #include "core/fpdfdoc/cpdf_bookmark.h"
 #include "core/fpdfdoc/cpdf_bookmarktree.h"
 #include "fpdfsdk/fsdk_define.h"