Format almost everything.

This CL was generated by running

git ls-files | grep -P "(\.h|\.cc)$" | grep -v 'sdk/' | grep -v 'rtc_base/ssl_' | \
grep -v 'fake_rtc_certificate_generator.h' | grep -v 'modules/audio_device/win/' | \
grep -v 'system_wrappers/source/clock.cc' | grep -v 'rtc_base/trace_event.h' | \
grep -v 'modules/audio_coding/codecs/ilbc/' | grep -v 'screen_capturer_mac.h' | \
grep -v 'spl_inl_mips.h' | grep -v 'data_size_unittest.cc' | grep -v 'timestamp_unittest.cc' \
| xargs clang-format -i ; git cl format

Most of these changes are clang-format grouping and reordering includes
differently.

Bug: webrtc:9340
Change-Id: Ic83ddbc169bfacd21883e381b5181c3dd4fe8a63
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/144051
Commit-Queue: Jonas Olsson <jonasolsson@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28505}
diff --git a/rtc_base/helpers_unittest.cc b/rtc_base/helpers_unittest.cc
index 8d8f900..b855872 100644
--- a/rtc_base/helpers_unittest.cc
+++ b/rtc_base/helpers_unittest.cc
@@ -8,11 +8,13 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include "rtc_base/helpers.h"
+
 #include <string.h>
+
 #include <string>
 
 #include "rtc_base/buffer.h"
-#include "rtc_base/helpers.h"
 #include "test/gtest.h"
 
 namespace rtc {