Change "http" to "https" in perf dashboard upload URL.

When uploading chromeOS perf data to Chrome team's live perf dashboard,
we need to upload with "https" instead of "http".  When we use http,
we get an HTML 405: "Method Not Allowed" error.

BUG=None
TEST=Verified that we can upload successfully to the live perf
dashboard with this change.

Change-Id: If2eb6a7c0bc75d02e7a47101318e9674624536e3
Reviewed-on: https://gerrit.chromium.org/gerrit/49672
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Queue: Dennis Jeffrey <dennisjeffrey@chromium.org>
Tested-by: Dennis Jeffrey <dennisjeffrey@chromium.org>
diff --git a/frontend/perf-dashboard/generate_perf_graphs.py b/frontend/perf-dashboard/generate_perf_graphs.py
index 95383b8..0b30951 100644
--- a/frontend/perf-dashboard/generate_perf_graphs.py
+++ b/frontend/perf-dashboard/generate_perf_graphs.py
@@ -48,7 +48,7 @@
 _WILDCARD = '*'
 _TELEMETRY_PERF_KEY_IDENTIFIER = 'TELEMETRY'
 _TELEMETRY_PERF_KEY_DELIMITER = '--'
-_NEW_DASH_UPLOAD_URL = 'http://chromeperf.appspot.com/add_point'
+_NEW_DASH_UPLOAD_URL = 'https://chromeperf.appspot.com/add_point'
 
 # Values that can be configured through options.
 # TODO(dennisjeffrey): Infer the tip-of-tree milestone dynamically once this