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}

rtc_base/sigslottester.h.pump

diff --git a/rtc_base/sigslottester.h.pump b/rtc_base/sigslottester.h.pump
index 381b791..1029a0f 100755
--- a/rtc_base/sigslottester.h.pump
+++ b/rtc_base/sigslottester.h.pump
@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef WEBRTC_RTC_BASE_SIGSLOTTESTER_H_
-#define WEBRTC_RTC_BASE_SIGSLOTTESTER_H_
+#ifndef RTC_BASE_SIGSLOTTESTER_H_
+#define RTC_BASE_SIGSLOTTESTER_H_
 
 // To generate sigslottester.h from sigslottester.h.pump, execute:
 // /home/build/google3/third_party/gtest/scripts/pump.py sigslottester.h.pump
@@ -35,8 +35,8 @@
 //   EXPECT_EQ("hello", capture);
 //   /* See unit-tests for more examples */
 
-#include "webrtc/rtc_base/constructormagic.h"
-#include "webrtc/rtc_base/sigslot.h"
+#include "rtc_base/constructormagic.h"
+#include "rtc_base/sigslot.h"
 
 namespace rtc {
 
@@ -99,4 +99,4 @@
 ]]
 }  // namespace rtc
 
-#endif  // WEBRTC_RTC_BASE_SIGSLOTTESTER_H_
+#endif  // RTC_BASE_SIGSLOTTESTER_H_