Add data dependency to event_log_visualizer.

This .wav file is an implicit data dependency, this CL adds this
information to the build system.

Bug: None
Change-Id: Ia953e63d4658debce3cecb93bb1f3e749fe52f54
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/166044
Reviewed-by: Ali Tofigh <alito@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30257}
diff --git a/rtc_tools/BUILD.gn b/rtc_tools/BUILD.gn
index 8ca20af..a37f210 100644
--- a/rtc_tools/BUILD.gn
+++ b/rtc_tools/BUILD.gn
@@ -323,7 +323,13 @@
       sources = [
         "rtc_event_log_visualizer/main.cc",
       ]
-
+      data = [
+        # If --wav_filename is not provided, event_log_visualizer uses
+        # EN_script2_F_sp2_B1.wav by default. This is a good default to use
+        # for example with flags --plot=all when there is no need to use a
+        # specific .wav file.
+        "../resources/audio_processing/conversational_speech/EN_script2_F_sp2_B1.wav",
+      ]
       deps = [
         ":event_log_visualizer_utils",
         "../api/neteq:neteq_api",