Use local dashboard for test uploads in perf_data_uploader.py

Use local dashboard for test uploads in perf_data_uploader.py

perf_data_uploader.py can upload perf data to the staging instance of
performance dashboard for testing / debugging. Unfortunately, the
staging instance is no longer available, instead, developers are advised
to use locally running instances of the performance dashboard.

This patch updates `perf_data_uploader.py` to use locally running
instance for test uploads and documents how such instance can be
obtained.

R=etiennej@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/7df053f84fc637eb672ffc440c90631fea207b7b

[ppi, 2015-10-22 14:26:23]

Description was changed from

==========
Use local dashboard for test uploads in perf_data_uploader.py

perf_data_uploader.py can upload perf data to the staging instance of
performance dashboard for testing / debugging. Unfortunately, the
staging instance is no longer available, instead, developers are advised
to use locally running instances of the performance dashboard.

This patch updates `perf_data_uploader.py` to use locally running
instance for test uploads and documents how such instance can be
obtained.
==========

to

==========
Use local dashboard for test uploads in perf_data_uploader.py

perf_data_uploader.py can upload perf data to the staging instance of
performance dashboard for testing / debugging. Unfortunately, the
staging instance is no longer available, instead, developers are advised
to use locally running instances of the performance dashboard.

This patch updates `perf_data_uploader.py` to use locally running
instance for test uploads and documents how such instance can be
obtained.
==========

[ppi, 2015-10-22 14:26:23]

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

[ppi, 2015-10-22 14:26:37]

Hi Etienne,

ptal.

[etiennej, 2015-10-22 14:55:42]

lgtm

[ppi, 2015-10-22 14:56:22]

Committed patchset #1 (id:1) manually as
7df053f84fc637eb672ffc440c90631fea207b7b (presubmit successful).