clean up render_pdfs:
     Remove unused headers
     replace dynamic memory wstream with null wstream.
     Use SkAutoTDelete when appropriate.
     Replace PdfRenderer class with short function: pdf_to_stream.
     Collapse render_pdf, process_input, tool_main_core functions
     Split out process_input_files function.
     Don't crash when no arguments given.
     print out max rss on each skp.
     prettier output

R=mtklein@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/463603002
4 files changed