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/modules/bitrate_controller/bitrate_controller_impl.h b/modules/bitrate_controller/bitrate_controller_impl.h
index 0934fa2..1bcb6ea 100644
--- a/modules/bitrate_controller/bitrate_controller_impl.h
+++ b/modules/bitrate_controller/bitrate_controller_impl.h
@@ -12,19 +12,19 @@
  *  and push the result to the encoder via VideoEncoderCallback.
  */
 
-#ifndef WEBRTC_MODULES_BITRATE_CONTROLLER_BITRATE_CONTROLLER_IMPL_H_
-#define WEBRTC_MODULES_BITRATE_CONTROLLER_BITRATE_CONTROLLER_IMPL_H_
+#ifndef MODULES_BITRATE_CONTROLLER_BITRATE_CONTROLLER_IMPL_H_
+#define MODULES_BITRATE_CONTROLLER_BITRATE_CONTROLLER_IMPL_H_
 
-#include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
+#include "modules/bitrate_controller/include/bitrate_controller.h"
 
 #include <list>
 #include <map>
 #include <utility>
 #include <vector>
 
-#include "webrtc/modules/bitrate_controller/send_side_bandwidth_estimation.h"
-#include "webrtc/rtc_base/constructormagic.h"
-#include "webrtc/rtc_base/criticalsection.h"
+#include "modules/bitrate_controller/send_side_bandwidth_estimation.h"
+#include "rtc_base/constructormagic.h"
+#include "rtc_base/criticalsection.h"
 
 namespace webrtc {
 
@@ -105,4 +105,4 @@
   RTC_DISALLOW_IMPLICIT_CONSTRUCTORS(BitrateControllerImpl);
 };
 }  // namespace webrtc
-#endif  // WEBRTC_MODULES_BITRATE_CONTROLLER_BITRATE_CONTROLLER_IMPL_H_
+#endif  // MODULES_BITRATE_CONTROLLER_BITRATE_CONTROLLER_IMPL_H_