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/utility/include/process_thread.h b/modules/utility/include/process_thread.h
index 6fa4e79..2168c27 100644
--- a/modules/utility/include/process_thread.h
+++ b/modules/utility/include/process_thread.h
@@ -8,17 +8,17 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef WEBRTC_MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
-#define WEBRTC_MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
+#ifndef MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
+#define MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
 
 #include <memory>
 
-#include "webrtc/typedefs.h"
+#include "typedefs.h"
 
 #if defined(WEBRTC_WIN)
 // Due to a bug in the std::unique_ptr implementation that ships with MSVS,
 // we need the full definition of QueuedTask, on Windows.
-#include "webrtc/rtc_base/task_queue.h"
+#include "rtc_base/task_queue.h"
 #else
 namespace rtc {
 class QueuedTask;
@@ -74,4 +74,4 @@
 
 }  // namespace webrtc
 
-#endif // WEBRTC_MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_
+#endif // MODULES_UTILITY_INCLUDE_PROCESS_THREAD_H_