SkPDF: move all pdf sources into src/pdf

cmake/CMakeLists.txt

 # Boilerplate.
 cmake_minimum_required (VERSION 3.1)   # First version with CMAKE_CXX_STANDARD.
 project (skimake)
 set (CMAKE_CXX_STANDARD 11)
 
 # Default to Release mode.  We're mainly targeting Skia users, not Skia developers.
 if (NOT CMAKE_BUILD_TYPE)
     set (CMAKE_BUILD_TYPE Release)
 endif ()
 
@@ skipping 186 matching lines @@
 else()
     remove_srcs(../src/images/*png*)
     remove_srcs(../src/images/*ico*)
     remove_srcs(../src/codec/*Png*)
     remove_srcs(../src/codec/*Ico*)
 endif()
 
 if (ZLIB_FOUND)
     list (APPEND private_includes ${ZLIB_INCLUDE_DIRS})
     list (APPEND libs             ${ZLIB_LIBRARIES})
-    remove_srcs(../src/doc/SkDocument_PDF_None.cpp)
+    remove_srcs(../src/pdf/SkDocument_PDF_None.cpp)
 else()
-    remove_srcs(../src/pdf/*.cpp ../src/doc/SkDocument_PDF.cpp)
+    remove_srcs(../src/pdf/*.cpp)
+    set (srcs ${srcs} ../src/pdf/SkDocument_PDF_None.cpp)
 endif()
 
 if (WEBP_INCLUDE_DIRS AND WEBP_LIBRARIES)
     list (APPEND private_includes ${WEBP_INCLUDE_DIRS})
     list (APPEND libs             ${WEBP_LIBRARIES})
     add_definitions(-DSK_CODEC_DECODES_WEBP)
 else()
     remove_srcs(../src/images/*webp*)
     remove_srcs(../src/codec/*Webp*)
 endif()
@@ skipping 106 matching lines @@
         file (APPEND ${skia_h_path} "#include \"${filename_component}\"\n")
       endif ()
     endforeach()
   endif()
 endforeach()
 file(APPEND ${skia_h_path} "\n#endif  // skia_DEFINED\n")
 
 # Now build a simple example app that uses Skia via libskia.so.
 add_executable(example example.cpp)
 target_link_libraries(example skia ${OPENGL_LIBRARIES})