Fixing WebRTC after moving from src/webrtc to src/

In https://webrtc-review.googlesource.com/c/src/+/1560 we moved WebRTC
from src/webrtc to src/ (in order to preserve an healthy git history).
This CL takes care of fixing header guards, #include paths, etc...

NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
TBR=tommi@webrtc.org


Bug: chromium:611808
Change-Id: Iea91618212bee0af16aa3f05071eab8f93706578
Reviewed-on: https://webrtc-review.googlesource.com/1561
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#19846}
diff --git a/audio/BUILD.gn b/audio/BUILD.gn
index 890de51..aa33192 100644
--- a/audio/BUILD.gn
+++ b/audio/BUILD.gn
@@ -153,9 +153,9 @@
       }
 
       data = [
-        "../../resources/voice_engine/audio_tiny16.wav",
-        "../../resources/voice_engine/audio_tiny48.wav",
-        "../../resources/voice_engine/audio_dtx16.wav",
+        "../resources/voice_engine/audio_tiny16.wav",
+        "../resources/voice_engine/audio_tiny48.wav",
+        "../resources/voice_engine/audio_dtx16.wav",
       ]
 
       if (!build_with_chromium && is_clang) {