clean up render_pdfs:

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

Committed: https://skia.googlesource.com/skia/+/8b2cb3391d75f0e7b522ab3180da833370f413bd

[hal.canary, 2014-08-11 19:57:05]

The CQ bit was checked by halcanary@google.com

[commit-bot: I haz the power, 2014-08-11 19:57:20]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/halcanary@google.com/463603002/20001

[commit-bot: I haz the power, 2014-08-11 19:57:21]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from a valid reviewer till 2014-08-12 01:57 UTC

[hal.canary, 2014-08-11 20:03:19]

ptal

[hal.canary, 2014-08-11 20:03:22]

The CQ bit was unchecked by halcanary@google.com

[mtklein, 2014-08-11 20:05:18]

lgtm

[mtklein, 2014-08-11 20:07:13]

The CQ bit was checked by mtklein@google.com

[commit-bot: I haz the power, 2014-08-11 20:08:21]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/halcanary@google.com/463603002/20001

[commit-bot: I haz the power, 2014-08-11 20:08:31]

Change committed as 8b2cb3391d75f0e7b522ab3180da833370f413bd