pdf viewer: fix a few warnings, and enable warning as errors

experimental/PdfViewer/pdf_viewer_main.cpp

 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkForceLinking.h"
 #include "SkGraphics.h"
 #include "SkImageDecoder.h"
 #include "SkImageEncoder.h"
 #include "SkOSFile.h"
 #include "SkPicture.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
@@ skipping 30 matching lines @@
     SkDebugf("\n");
 }
 
 /** Replaces the extension of a file.
  * @param path File name whose extension will be changed.
  * @param old_extension The old extension.
  * @param new_extension The new extension.
  * @returns false if the file did not has the expected extension.
  *  if false is returned, contents of path are undefined.
  */
+/*
 static bool replace_filename_extension(SkString* path,
                                        const char old_extension[],
                                        const char new_extension[]) {
     if (path->endsWith(old_extension)) {
         path->remove(path->size() - strlen(old_extension),
                      strlen(old_extension));
         if (!path->endsWith(".")) {
             return false;
         }
         path->append(new_extension);
         return true;
     }
     return false;
 }
-
+*/
 /** Builds the output filename. path = dir/name, and it replaces expected
  * .skp extension with .pdf extention.
  * @param path Output filename.
  * @param name The name of the file.
  * @returns false if the file did not has the expected extension.
  *  if false is returned, contents of path are undefined.
  */
+
+/*
 static bool make_output_filepath(SkString* path, const SkString& dir,
                                  const SkString& name) {
     sk_tools::make_filepath(path, dir, name);
     return replace_filename_extension(path,
                                       PDF_FILE_EXTENSION,
                                       PNG_FILE_EXTENSION);
 }
-
+*/
 /** Write the output of pdf renderer to a file.
  * @param outputDir Output dir.
  * @param inputFilename The skp file that was read.
  * @param renderer The object responsible to write the pdf file.
  */
+/*
 static bool write_output(const SkString& outputDir,
                          const SkString& inputFilename,
                          const SkPdfViewer& renderer) {
     if (outputDir.isEmpty()) {
         SkDynamicMemoryWStream stream;
         renderer.write(&stream);
         return true;
     }
 
     SkString outputPath;
     if (!make_output_filepath(&outputPath, outputDir, inputFilename)) {
         return false;
     }
 
     SkFILEWStream stream(outputPath.c_str());
     if (!stream.isValid()) {
         SkDebugf("Could not write to file %s\n", outputPath.c_str());
         return false;
     }
     renderer.write(&stream);
 
     return true;
 }
-
+*/
 /** Reads an skp file, renders it to pdf and writes the output to a pdf file
  * @param inputPath The skp file to be read.
  * @param outputDir Output dir.
  * @param renderer The object responsible to render the skp object into pdf.
  */
 static bool parse_pdf(const SkString& inputPath, const SkString& outputDir,
                        SkPdfViewer& renderer) {
     SkString inputFilename;
     sk_tools::get_basename(&inputFilename, inputPath);
 
@@ skipping 97 matching lines @@
     }
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif