Delete root header file typedef.h.

Usage replaced with stdint.h, rtc_base/system/arch.h and
rtc_base/system/unused.h, as appropriate.

Bug: webrtc:6854
Change-Id: I97225465d14b969903d92979e2df3c3c05d35f18
Reviewed-on: https://webrtc-review.googlesource.com/90249
Reviewed-by: Niklas Enbom <niklas.enbom@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24100}

system_wrappers/source/cpu_features.cc

@@ -10,13 +10,13 @@
 
 // Parts of this file derived from Chromium's base/cpu.cc.
 
+#include "rtc_base/system/arch.h"
 #include "system_wrappers/include/cpu_features_wrapper.h"
 
 #if defined(WEBRTC_ARCH_X86_FAMILY) && defined(_MSC_VER)
 #include <intrin.h>
 #endif
 
-#include "typedefs.h"  // NOLINT(build/include)
 
 // No CPU feature is available => straight C path.
 int GetCPUInfoNoASM(CPUFeature feature) {

system_wrappers/source/cpu_features_linux.c

@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <link.h>
 #endif
+#include "rtc_base/system/arch.h"
 #include "system_wrappers/include/cpu_features_wrapper.h"
 
 #if defined(WEBRTC_ARCH_ARM_FAMILY)

system_wrappers/source/event_timer_win.h

@@ -11,12 +11,12 @@
 #ifndef SYSTEM_WRAPPERS_SOURCE_EVENT_WIN_H_
 #define SYSTEM_WRAPPERS_SOURCE_EVENT_WIN_H_
 
+#include <stdint.h>
+
 #include <windows.h>
 
 #include "system_wrappers/include/event_wrapper.h"
 
-#include "typedefs.h"  // NOLINT(build/include)
-
 namespace webrtc {
 
 class EventTimerWin : public EventTimerWrapper {