Fix the name of the file generated by generate_sslroots.py.

WebRTC filenames use underscores to separate words so the ssl roots
file is rtc_base/ssl_roots.h instead of rtc_base/sslroots.h.

Bug: chromium:978779
Change-Id: I2fa11c38a566e177775deb3d42230d956efc8ccc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/173800
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31132}
diff --git a/tools_webrtc/sslroots/generate_sslroots.py b/tools_webrtc/sslroots/generate_sslroots.py
index 65751f1..7d8bf14 100644
--- a/tools_webrtc/sslroots/generate_sslroots.py
+++ b/tools_webrtc/sslroots/generate_sslroots.py
@@ -25,7 +25,7 @@
 import re
 import string
 
-_GENERATED_FILE = 'sslroots.h'
+_GENERATED_FILE = 'ssl_roots.h'
 _PREFIX = '__generated__'
 _EXTENSION = '.crt'
 _SUBJECT_NAME_ARRAY = 'subject_name'