pdfviewer: make pdfviewer compile on mac

experimental/PdfViewer/pdf_viewer_main.cpp

 #include "SkCanvas.h"
 #include "SkCommandLineFlags.h"
 #include "SkDevice.h"
 #include "SkGraphics.h"
 #include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkOSFile.h"
 #include "SkPicture.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
@@ skipping 65 matching lines @@
         }
         if (page >= 0) {
             path->appendf("%i.", page);
         }
         path->append(new_extension);
         return true;
     }
     return false;
 }
 
-void make_filepath(SkString* path, const SkString& dir, const SkString& name) {
+static void make_filepath(SkString* path, const SkString& dir, const SkString& name) {
     size_t len = dir.size();
     path->set(dir);
     if (0 < len  && '/' != dir[len - 1]) {
         path->append("/");
     }
     path->append(name);
 }
 
-bool is_path_seperator(const char chr) {
+static bool is_path_seperator(const char chr) {
 #if defined(SK_BUILD_FOR_WIN)
     return chr == '\\' || chr == '/';
 #else
     return chr == '/';
 #endif
 }
 
-void get_basename(SkString* basename, const SkString& path) {
+static void get_basename(SkString* basename, const SkString& path) {
     if (path.size() == 0) {
         basename->reset();
         return;
     }
 
     size_t end = path.size() - 1;
 
     // Paths pointing to directories often have a trailing slash,
     // we remove it so the name is not empty
     if (is_path_seperator(path[end])) {
@@ skipping 258 matching lines @@
     }
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif