Adding errorprone to LIB_TO_LICENSE_DICT.

Bug: webrtc:8390
Change-Id: I17dc06901ba8336b091351ab2369694a0928afe3
No-Try: True
Reviewed-on: https://webrtc-review.googlesource.com/9164
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Reviewed-by: Edward Lemur <ehmaldonado@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20282}
diff --git a/tools_webrtc/libs/generate_licenses.py b/tools_webrtc/libs/generate_licenses.py
index e3b05a8..1bfcb64 100755
--- a/tools_webrtc/libs/generate_licenses.py
+++ b/tools_webrtc/libs/generate_licenses.py
@@ -24,6 +24,7 @@
 LIB_TO_LICENSES_DICT = {
     'android_tools': ['third_party/android_tools/LICENSE'],
     'boringssl': ['third_party/boringssl/src/LICENSE'],
+    'errorprone': ['third_party/errorprone/LICENSE'],
     'expat': ['third_party/expat/files/COPYING'],
     'ijar': ['third_party/ijar/LICENSE'],
     'jsoncpp': ['third_party/jsoncpp/LICENSE'],