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}

api/audio_codecs/BUILD.gn

@@ -31,7 +31,6 @@ rtc_source_set("audio_codecs_api") {
   deps = [
     "..:array_view",
     "../..:webrtc_common",
-    "../../:typedefs",
     "../../rtc_base:checks",
     "../../rtc_base:deprecation",
     "../../rtc_base:rtc_base_approved",

api/audio_codecs/audio_decoder.h

@@ -18,7 +18,6 @@
 #include "api/array_view.h"
 #include "rtc_base/buffer.h"
 #include "rtc_base/constructormagic.h"
-#include "typedefs.h"  // NOLINT(build/include)
 
 namespace webrtc {
 

api/audio_codecs/audio_encoder.h

@@ -20,7 +20,6 @@
 #include "api/array_view.h"
 #include "rtc_base/buffer.h"
 #include "rtc_base/deprecation.h"
-#include "typedefs.h"  // NOLINT(build/include)
 
 namespace webrtc {