Improve the command line interface for perf dashboard upload.

Improve the command line interface for perf dashboard upload.

This patch:
 - renames `perf_id` which really is bot name and ends up being the
   value for the "bot" field in the data being sent to `bot_name`.
 - adds an explicit `--upload` flag for perf test / benchmark runner
   (rather than making the upload call based on the collective presence
   of all optional upload parameters)

R=etiennej@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/ccaee11a5bfbed231753bc92e98cc2e5b1270a49

[ppi, 2015-10-23 15:57:06]

Description was changed from

==========
Improve the command line interface for perf dashboard upload.

This patch:
 - renames `perf_id` which really is bot name and ends up being the
   value for the "bot" field in the data being sent to `bot_name`.
 - adds an explicit `--upload` flag for perf test / benchmark runner
   (rather than making the upload call based on the collective presence
   of all optional upload parameters)
==========

to

==========
Improve the command line interface for perf dashboard upload.

This patch:
 - renames `perf_id` which really is bot name and ends up being the
   value for the "bot" field in the data being sent to `bot_name`.
 - adds an explicit `--upload` flag for perf test / benchmark runner
   (rather than making the upload call based on the collective presence
   of all optional upload parameters)
==========

[ppi, 2015-10-23 15:57:06]

ppi@chromium.org changed reviewers:
+ etiennej@chromium.org

[ppi, 2015-10-23 15:57:20]

Hi Etienne,

ptal.

[ppi, 2015-10-23 15:58:19]

ppi@chromium.org changed reviewers:
+ vtl@google.com

[ppi, 2015-10-23 15:59:05]

+ Trung, as Etienne left for the weekend

Trung, can you tal?

[etiennej, 2015-10-26 08:03:37]

lgtm

[ppi, 2015-10-26 08:12:33]

Committed patchset #1 (id:1) manually as
ccaee11a5bfbed231753bc92e98cc2e5b1270a49 (presubmit successful).